diff --git a/doc/THIRD-PARTY.md b/doc/THIRD-PARTY.md
index be1fdda4c..9c1718c39 100644
--- a/doc/THIRD-PARTY.md
+++ b/doc/THIRD-PARTY.md
@@ -15,9 +15,6 @@ This file lists bundled packages and their associated licensing terms.
   Copyright (C) 2013, Jonathan Hartley.
 * The Fcrypt library located under thirdparty/fcrypt/.
   Copyright (C) 2000, 2001, 2004 Carey Evans.
-* The Oset library located under thirdparty/oset/.
-  Copyright (C) 2010, BlueDynamics Alliance, Austria.
-  Copyright (C) 2009, Raymond Hettinger, and others.
 * The PrettyPrint library located under thirdparty/prettyprint/.
   Copyright (C) 2010, Chris Hall.
 * The SocksiPy library located under thirdparty/socks/.
diff --git a/lib/core/datatype.py b/lib/core/datatype.py
index cfc4dd02f..2285948c3 100644
--- a/lib/core/datatype.py
+++ b/lib/core/datatype.py
@@ -5,6 +5,7 @@ Copyright (c) 2006-2019 sqlmap developers (http://sqlmap.org/)
 See the file 'LICENSE' for copying permission
 """
 
+import collections
 import copy
 import types
 
@@ -140,3 +141,61 @@ class LRUDict(object):
 
     def keys(self):
         return self.cache.keys()
+
+# Reference: https://code.activestate.com/recipes/576694/
+class OrderedSet(collections.MutableSet):
+    def __init__(self, iterable=None):
+        self.end = end = []
+        end += [None, end, end]         # sentinel node for doubly linked list
+        self.map = {}                   # key --> [key, prev, next]
+        if iterable is not None:
+            self |= iterable
+
+    def __len__(self):
+        return len(self.map)
+
+    def __contains__(self, key):
+        return key in self.map
+
+    def add(self, key):
+        if key not in self.map:
+            end = self.end
+            curr = end[1]
+            curr[2] = end[1] = self.map[key] = [key, curr, end]
+
+    def discard(self, key):
+        if key in self.map:
+            key, prev, next = self.map.pop(key)
+            prev[2] = next
+            next[1] = prev
+
+    def __iter__(self):
+        end = self.end
+        curr = end[2]
+        while curr is not end:
+            yield curr[0]
+            curr = curr[2]
+
+    def __reversed__(self):
+        end = self.end
+        curr = end[1]
+        while curr is not end:
+            yield curr[0]
+            curr = curr[1]
+
+    def pop(self, last=True):
+        if not self:
+            raise KeyError('set is empty')
+        key = self.end[1][0] if last else self.end[2][0]
+        self.discard(key)
+        return key
+
+    def __repr__(self):
+        if not self:
+            return '%s()' % (self.__class__.__name__,)
+        return '%s(%r)' % (self.__class__.__name__, list(self))
+
+    def __eq__(self, other):
+        if isinstance(other, OrderedSet):
+            return len(self) == len(other) and list(self) == list(other)
+        return set(self) == set(other)
diff --git a/lib/core/option.py b/lib/core/option.py
index 3c331d3d6..adb3291e0 100644
--- a/lib/core/option.py
+++ b/lib/core/option.py
@@ -16,7 +16,6 @@ import sys
 import tempfile
 import threading
 import time
-import urllib2
 
 import lib.controller.checks
 import lib.core.common
@@ -66,6 +65,7 @@ from lib.core.data import mergedOptions
 from lib.core.data import queries
 from lib.core.datatype import AttribDict
 from lib.core.datatype import InjectionDict
+from lib.core.datatype import OrderedSet
 from lib.core.defaults import defaults
 from lib.core.dicts import DBMS_DICT
 from lib.core.dicts import DUMP_REPLACEMENTS
@@ -149,7 +149,6 @@ from lib.utils.search import search
 from lib.utils.purge import purge
 from thirdparty.keepalive import keepalive
 from thirdparty.multipart import multipartpost
-from thirdparty.oset.pyoset import oset
 from thirdparty.six.moves import http_client as _http_client
 from thirdparty.six.moves import http_cookiejar as _http_cookiejar
 from thirdparty.six.moves import urllib as _urllib
@@ -2023,7 +2022,7 @@ def _setKnowledgeBaseAttributes(flushAll=True):
         kb.preprocessFunctions = []
         kb.skipVulnHost = None
         kb.tamperFunctions = []
-        kb.targets = oset()
+        kb.targets = OrderedSet()
         kb.testedParams = set()
         kb.userAgents = None
         kb.vainRun = True
diff --git a/lib/core/settings.py b/lib/core/settings.py
index 658386be1..df16b96a4 100644
--- a/lib/core/settings.py
+++ b/lib/core/settings.py
@@ -17,7 +17,7 @@ from lib.core.enums import DBMS_DIRECTORY_NAME
 from lib.core.enums import OS
 
 # sqlmap version (<major>.<minor>.<month>.<monthly commit>)
-VERSION = "1.3.3.60"
+VERSION = "1.3.3.61"
 TYPE = "dev" if VERSION.count('.') > 2 and VERSION.split('.')[-1] != '0' else "stable"
 TYPE_COLORS = {"dev": 33, "stable": 90, "pip": 34}
 VERSION_STRING = "sqlmap/%s#%s" % ('.'.join(VERSION.split('.')[:-1]) if VERSION.count('.') > 2 and VERSION.split('.')[-1] == '0' else VERSION, TYPE)
diff --git a/lib/core/subprocessng.py b/lib/core/subprocessng.py
index ed7be6fdb..19fd1a06d 100644
--- a/lib/core/subprocessng.py
+++ b/lib/core/subprocessng.py
@@ -85,7 +85,7 @@ class Popen(subprocess.Popen):
         getattr(self, which).close()
         setattr(self, which, None)
 
-    if subprocess.mswindows:
+    if IS_WIN:
         def send(self, input):
             if not self.stdin:
                 return None
diff --git a/lib/parse/sitemap.py b/lib/parse/sitemap.py
index a3a1d2cd0..b369ab17a 100644
--- a/lib/parse/sitemap.py
+++ b/lib/parse/sitemap.py
@@ -10,9 +10,9 @@ import re
 from lib.core.common import readInput
 from lib.core.data import kb
 from lib.core.data import logger
+from lib.core.datatype import OrderedSet
 from lib.core.exception import SqlmapSyntaxException
 from lib.request.connect import Connect as Request
-from thirdparty.oset.pyoset import oset
 from thirdparty.six.moves import http_client as _http_client
 
 abortedFlag = None
@@ -26,7 +26,7 @@ def parseSitemap(url, retVal=None):
     try:
         if retVal is None:
             abortedFlag = False
-            retVal = oset()
+            retVal = OrderedSet()
 
         try:
             content = Request.getPage(url=url, raise404=True)[0] if not abortedFlag else ""
diff --git a/lib/takeover/web.py b/lib/takeover/web.py
index 72842f5a5..21b3b5fc7 100644
--- a/lib/takeover/web.py
+++ b/lib/takeover/web.py
@@ -37,6 +37,7 @@ from lib.core.data import conf
 from lib.core.data import kb
 from lib.core.data import logger
 from lib.core.data import paths
+from lib.core.datatype import OrderedSet
 from lib.core.enums import DBMS
 from lib.core.enums import HTTP_HEADER
 from lib.core.enums import OS
@@ -50,7 +51,6 @@ from lib.core.settings import SHELL_RUNCMD_EXE_TAG
 from lib.core.settings import SHELL_WRITABLE_DIR_TAG
 from lib.core.settings import VIEWSTATE_REGEX
 from lib.request.connect import Connect as Request
-from thirdparty.oset.pyoset import oset
 from thirdparty.six.moves import urllib as _urllib
 
 class Web:
@@ -254,7 +254,7 @@ class Web:
 
         directories = list(arrayizeValue(getManualDirectories()))
         directories.extend(getAutoDirectories())
-        directories = list(oset(directories))
+        directories = list(OrderedSet(directories))
 
         path = _urllib.parse.urlparse(conf.url).path or '/'
         path = re.sub(r"/[^/]*\.\w+\Z", '/', path)
diff --git a/lib/utils/crawler.py b/lib/utils/crawler.py
index c44735f86..f6a75f91d 100644
--- a/lib/utils/crawler.py
+++ b/lib/utils/crawler.py
@@ -22,6 +22,7 @@ from lib.core.common import urldecode
 from lib.core.data import conf
 from lib.core.data import kb
 from lib.core.data import logger
+from lib.core.datatype import OrderedSet
 from lib.core.enums import MKSTEMP_PREFIX
 from lib.core.exception import SqlmapConnectionException
 from lib.core.exception import SqlmapSyntaxException
@@ -31,7 +32,6 @@ from lib.core.threads import runThreads
 from lib.parse.sitemap import parseSitemap
 from lib.request.connect import Connect as Request
 from thirdparty.beautifulsoup.beautifulsoup import BeautifulSoup
-from thirdparty.oset.pyoset import oset
 from thirdparty.six.moves import http_client as _http_client
 from thirdparty.six.moves import urllib as _urllib
 
@@ -39,7 +39,7 @@ def crawl(target):
     try:
         visited = set()
         threadData = getCurrentThreadData()
-        threadData.shared.value = oset()
+        threadData.shared.value = OrderedSet()
 
         def crawlThread():
             threadData = getCurrentThreadData()
diff --git a/lib/utils/hash.py b/lib/utils/hash.py
index 21dc6b965..968ca6772 100644
--- a/lib/utils/hash.py
+++ b/lib/utils/hash.py
@@ -45,7 +45,6 @@ from hashlib import sha224
 from hashlib import sha256
 from hashlib import sha384
 from hashlib import sha512
-from Queue import Queue
 
 from lib.core.common import Backend
 from lib.core.common import checkFile
@@ -68,6 +67,7 @@ from lib.core.convert import utf8encode
 from lib.core.data import conf
 from lib.core.data import kb
 from lib.core.data import logger
+from lib.core.datatype import OrderedSet
 from lib.core.enums import DBMS
 from lib.core.enums import HASH
 from lib.core.enums import MKSTEMP_PREFIX
@@ -87,9 +87,9 @@ from lib.core.settings import UNICODE_ENCODING
 from lib.core.settings import ROTATING_CHARS
 from lib.core.wordlist import Wordlist
 from thirdparty.colorama.initialise import init as coloramainit
-from thirdparty.oset.pyoset import oset
 from thirdparty.pydes.pyDes import des
 from thirdparty.pydes.pyDes import CBC
+from thirdparty.six.moves import queue as _queue
 
 def mysql_passwd(password, uppercase=True):
     """
@@ -561,7 +561,7 @@ def storeHashesToFile(attack_dict):
     if not attack_dict:
         return
 
-    items = oset()
+    items = OrderedSet()
 
     for user, hashes in attack_dict.items():
         for hash_ in hashes:
@@ -1059,7 +1059,7 @@ def dictionaryAttack(attack_dict):
                         warnMsg += "not supported on this platform"
                         singleTimeWarnMessage(warnMsg)
 
-                        retVal = Queue()
+                        retVal = _queue.Queue()
                         _bruteProcessVariantA(attack_info, hash_regex, suffix, retVal, 0, 1, kb.wordlists, custom_wordlist, conf.api)
 
                 except KeyboardInterrupt:
@@ -1150,7 +1150,7 @@ def dictionaryAttack(attack_dict):
                             class Value():
                                 pass
 
-                            retVal = Queue()
+                            retVal = _queue.Queue()
                             found_ = Value()
                             found_.value = False
 
diff --git a/thirdparty/oset/LICENSE.txt b/thirdparty/oset/LICENSE.txt
deleted file mode 100644
index aef85dda3..000000000
--- a/thirdparty/oset/LICENSE.txt
+++ /dev/null
@@ -1,29 +0,0 @@
-License
-=======
-
-Copyright (c) 2009, Raymond Hettinger, and others
-All rights reserved.
-
-Package structured based on the one developed to odict
-Copyright (c) 2010, BlueDynamics Alliance, Austria
-
-
-* Redistributions of source code must retain the above copyright notice, this 
-  list of conditions and the following disclaimer.
-* Redistributions in binary form must reproduce the above copyright notice, this 
-  list of conditions and the following disclaimer in the documentation and/or 
-  other materials provided with the distribution.
-* Neither the name of the BlueDynamics Alliance nor the names of its 
-  contributors may be used to endorse or promote products derived from this 
-  software without specific prior written permission.
-      
-THIS SOFTWARE IS PROVIDED BY BlueDynamics Alliance ``AS IS`` AND ANY
-EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-DISCLAIMED. IN NO EVENT SHALL BlueDynamics Alliance BE LIABLE FOR ANY
-DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/thirdparty/oset/__init__.py b/thirdparty/oset/__init__.py
deleted file mode 100644
index 688b31e92..000000000
--- a/thirdparty/oset/__init__.py
+++ /dev/null
@@ -1,3 +0,0 @@
-"""Main Ordered Set module """
-
-from pyoset import oset
diff --git a/thirdparty/oset/_abc.py b/thirdparty/oset/_abc.py
deleted file mode 100644
index ae6db9706..000000000
--- a/thirdparty/oset/_abc.py
+++ /dev/null
@@ -1,476 +0,0 @@
-#!/usr/bin/env python2
-# -*- mode:python; tab-width: 2; coding: utf-8 -*-
-
-"""Partially backported python ABC classes"""
-
-from __future__ import absolute_import
-
-import sys
-import types
-
-if sys.version_info > (2, 6):
-    raise ImportError("Use native ABC classes istead of this one.")
-
-
-# Instance of old-style class
-class _C:
-    pass
-
-_InstanceType = type(_C())
-
-
-def abstractmethod(funcobj):
-    """A decorator indicating abstract methods.
-
-    Requires that the metaclass is ABCMeta or derived from it.  A
-    class that has a metaclass derived from ABCMeta cannot be
-    instantiated unless all of its abstract methods are overridden.
-    The abstract methods can be called using any of the normal
-    'super' call mechanisms.
-
-    Usage:
-
-        class C:
-            __metaclass__ = ABCMeta
-            @abstractmethod
-            def my_abstract_method(self, ...):
-                ...
-    """
-    funcobj.__isabstractmethod__ = True
-    return funcobj
-
-
-class ABCMeta(type):
-
-    """Metaclass for defining Abstract Base Classes (ABCs).
-
-    Use this metaclass to create an ABC.  An ABC can be subclassed
-    directly, and then acts as a mix-in class.  You can also register
-    unrelated concrete classes (even built-in classes) and unrelated
-    ABCs as 'virtual subclasses' -- these and their descendants will
-    be considered subclasses of the registering ABC by the built-in
-    issubclass() function, but the registering ABC won't show up in
-    their MRO (Method Resolution Order) nor will method
-    implementations defined by the registering ABC be callable (not
-    even via super()).
-
-    """
-
-    # A global counter that is incremented each time a class is
-    # registered as a virtual subclass of anything.  It forces the
-    # negative cache to be cleared before its next use.
-    _abc_invalidation_counter = 0
-
-    def __new__(mcls, name, bases, namespace):
-        cls = super(ABCMeta, mcls).__new__(mcls, name, bases, namespace)
-        # Compute set of abstract method names
-        abstracts = set(name
-                     for name, value in namespace.items()
-                     if getattr(value, "__isabstractmethod__", False))
-        for base in bases:
-            for name in getattr(base, "__abstractmethods__", set()):
-                value = getattr(cls, name, None)
-                if getattr(value, "__isabstractmethod__", False):
-                    abstracts.add(name)
-        cls.__abstractmethods__ = frozenset(abstracts)
-        # Set up inheritance registry
-        cls._abc_registry = set()
-        cls._abc_cache = set()
-        cls._abc_negative_cache = set()
-        cls._abc_negative_cache_version = ABCMeta._abc_invalidation_counter
-        return cls
-
-    def register(cls, subclass):
-        """Register a virtual subclass of an ABC."""
-        if not isinstance(subclass, (type, types.ClassType)):
-            raise TypeError("Can only register classes")
-        if issubclass(subclass, cls):
-            return  # Already a subclass
-        # Subtle: test for cycles *after* testing for "already a subclass";
-        # this means we allow X.register(X) and interpret it as a no-op.
-        if issubclass(cls, subclass):
-            # This would create a cycle, which is bad for the algorithm below
-            raise RuntimeError("Refusing to create an inheritance cycle")
-        cls._abc_registry.add(subclass)
-        ABCMeta._abc_invalidation_counter += 1  # Invalidate negative cache
-
-    def _dump_registry(cls, file=None):
-        """Debug helper to print the ABC registry."""
-        print >> file, "Class: %s.%s" % (cls.__module__, cls.__name__)
-        print >> file, "Inv.counter: %s" % ABCMeta._abc_invalidation_counter
-        for name in sorted(cls.__dict__.keys()):
-            if name.startswith("_abc_"):
-                value = getattr(cls, name)
-                print >> file, "%s: %r" % (name, value)
-
-    def __instancecheck__(cls, instance):
-        """Override for isinstance(instance, cls)."""
-        # Inline the cache checking when it's simple.
-        subclass = getattr(instance, '__class__', None)
-        if subclass in cls._abc_cache:
-            return True
-        subtype = type(instance)
-        # Old-style instances
-        if subtype is _InstanceType:
-            subtype = subclass
-        if subtype is subclass or subclass is None:
-            if (cls._abc_negative_cache_version ==
-                ABCMeta._abc_invalidation_counter and
-                subtype in cls._abc_negative_cache):
-                return False
-            # Fall back to the subclass check.
-            return cls.__subclasscheck__(subtype)
-        return (cls.__subclasscheck__(subclass) or
-                cls.__subclasscheck__(subtype))
-
-    def __subclasscheck__(cls, subclass):
-        """Override for issubclass(subclass, cls)."""
-        # Check cache
-        if subclass in cls._abc_cache:
-            return True
-        # Check negative cache; may have to invalidate
-        if cls._abc_negative_cache_version < ABCMeta._abc_invalidation_counter:
-            # Invalidate the negative cache
-            cls._abc_negative_cache = set()
-            cls._abc_negative_cache_version = ABCMeta._abc_invalidation_counter
-        elif subclass in cls._abc_negative_cache:
-            return False
-        # Check the subclass hook
-        ok = cls.__subclasshook__(subclass)
-        if ok is not NotImplemented:
-            assert isinstance(ok, bool)
-            if ok:
-                cls._abc_cache.add(subclass)
-            else:
-                cls._abc_negative_cache.add(subclass)
-            return ok
-        # Check if it's a direct subclass
-        if cls in getattr(subclass, '__mro__', ()):
-            cls._abc_cache.add(subclass)
-            return True
-        # Check if it's a subclass of a registered class (recursive)
-        for rcls in cls._abc_registry:
-            if issubclass(subclass, rcls):
-                cls._abc_cache.add(subclass)
-                return True
-        # Check if it's a subclass of a subclass (recursive)
-        for scls in cls.__subclasses__():
-            if issubclass(subclass, scls):
-                cls._abc_cache.add(subclass)
-                return True
-        # No dice; update negative cache
-        cls._abc_negative_cache.add(subclass)
-        return False
-
-
-def _hasattr(C, attr):
-    try:
-        return any(attr in B.__dict__ for B in C.__mro__)
-    except AttributeError:
-        # Old-style class
-        return hasattr(C, attr)
-
-
-class Sized:
-    __metaclass__ = ABCMeta
-
-    @abstractmethod
-    def __len__(self):
-        return 0
-
-    @classmethod
-    def __subclasshook__(cls, C):
-        if cls is Sized:
-            if _hasattr(C, "__len__"):
-                return True
-        return NotImplemented
-
-
-class Container:
-    __metaclass__ = ABCMeta
-
-    @abstractmethod
-    def __contains__(self, x):
-        return False
-
-    @classmethod
-    def __subclasshook__(cls, C):
-        if cls is Container:
-            if _hasattr(C, "__contains__"):
-                return True
-        return NotImplemented
-
-
-class Iterable:
-    __metaclass__ = ABCMeta
-
-    @abstractmethod
-    def __iter__(self):
-        while False:
-            yield None
-
-    @classmethod
-    def __subclasshook__(cls, C):
-        if cls is Iterable:
-            if _hasattr(C, "__iter__"):
-                return True
-        return NotImplemented
-
-Iterable.register(str)
-
-
-class Set(Sized, Iterable, Container):
-    """A set is a finite, iterable container.
-
-    This class provides concrete generic implementations of all
-    methods except for __contains__, __iter__ and __len__.
-
-    To override the comparisons (presumably for speed, as the
-    semantics are fixed), all you have to do is redefine __le__ and
-    then the other operations will automatically follow suit.
-    """
-
-    def __le__(self, other):
-        if not isinstance(other, Set):
-            return NotImplemented
-        if len(self) > len(other):
-            return False
-        for elem in self:
-            if elem not in other:
-                return False
-        return True
-
-    def __lt__(self, other):
-        if not isinstance(other, Set):
-            return NotImplemented
-        return len(self) < len(other) and self.__le__(other)
-
-    def __gt__(self, other):
-        if not isinstance(other, Set):
-            return NotImplemented
-        return other < self
-
-    def __ge__(self, other):
-        if not isinstance(other, Set):
-            return NotImplemented
-        return other <= self
-
-    def __eq__(self, other):
-        if not isinstance(other, Set):
-            return NotImplemented
-        return len(self) == len(other) and self.__le__(other)
-
-    def __ne__(self, other):
-        return not (self == other)
-
-    @classmethod
-    def _from_iterable(cls, it):
-        '''Construct an instance of the class from any iterable input.
-
-        Must override this method if the class constructor signature
-        does not accept an iterable for an input.
-        '''
-        return cls(it)
-
-    def __and__(self, other):
-        if not isinstance(other, Iterable):
-            return NotImplemented
-        return self._from_iterable(value for value in other if value in self)
-
-    def isdisjoint(self, other):
-        for value in other:
-            if value in self:
-                return False
-        return True
-
-    def __or__(self, other):
-        if not isinstance(other, Iterable):
-            return NotImplemented
-        chain = (e for s in (self, other) for e in s)
-        return self._from_iterable(chain)
-
-    def __sub__(self, other):
-        if not isinstance(other, Set):
-            if not isinstance(other, Iterable):
-                return NotImplemented
-            other = self._from_iterable(other)
-        return self._from_iterable(value for value in self
-                                   if value not in other)
-
-    def __xor__(self, other):
-        if not isinstance(other, Set):
-            if not isinstance(other, Iterable):
-                return NotImplemented
-            other = self._from_iterable(other)
-        return (self - other) | (other - self)
-
-    # Sets are not hashable by default, but subclasses can change this
-    __hash__ = None
-
-    def _hash(self):
-        """Compute the hash value of a set.
-
-        Note that we don't define __hash__: not all sets are hashable.
-        But if you define a hashable set type, its __hash__ should
-        call this function.
-
-        This must be compatible __eq__.
-
-        All sets ought to compare equal if they contain the same
-        elements, regardless of how they are implemented, and
-        regardless of the order of the elements; so there's not much
-        freedom for __eq__ or __hash__.  We match the algorithm used
-        by the built-in frozenset type.
-        """
-        MAX = sys.maxint
-        MASK = 2 * MAX + 1
-        n = len(self)
-        h = 1927868237 * (n + 1)
-        h &= MASK
-        for x in self:
-            hx = hash(x)
-            h ^= (hx ^ (hx << 16) ^ 89869747) * 3644798167
-            h &= MASK
-        h = h * 69069 + 907133923
-        h &= MASK
-        if h > MAX:
-            h -= MASK + 1
-        if h == -1:
-            h = 590923713
-        return h
-
-Set.register(frozenset)
-
-
-class MutableSet(Set):
-
-    @abstractmethod
-    def add(self, value):
-        """Add an element."""
-        raise NotImplementedError
-
-    @abstractmethod
-    def discard(self, value):
-        """Remove an element.  Do not raise an exception if absent."""
-        raise NotImplementedError
-
-    def remove(self, value):
-        """Remove an element. If not a member, raise a KeyError."""
-        if value not in self:
-            raise KeyError(value)
-        self.discard(value)
-
-    def pop(self):
-        """Return the popped value.  Raise KeyError if empty."""
-        it = iter(self)
-        try:
-            value = next(it)
-        except StopIteration:
-            raise KeyError
-        self.discard(value)
-        return value
-
-    def clear(self):
-        """This is slow (creates N new iterators!) but effective."""
-        try:
-            while True:
-                self.pop()
-        except KeyError:
-            pass
-
-    def __ior__(self, it):
-        for value in it:
-            self.add(value)
-        return self
-
-    def __iand__(self, it):
-        for value in (self - it):
-            self.discard(value)
-        return self
-
-    def __ixor__(self, it):
-        if not isinstance(it, Set):
-            it = self._from_iterable(it)
-        for value in it:
-            if value in self:
-                self.discard(value)
-            else:
-                self.add(value)
-        return self
-
-    def __isub__(self, it):
-        for value in it:
-            self.discard(value)
-        return self
-
-MutableSet.register(set)
-
-
-class OrderedSet(MutableSet):
-
-    def __init__(self, iterable=None):
-        self.end = end = []
-        end += [None, end, end]         # sentinel node for doubly linked list
-        self.map = {}                   # key --> [key, prev, next]
-        if iterable is not None:
-            self |= iterable
-
-    def __len__(self):
-        return len(self.map)
-
-    def __contains__(self, key):
-        return key in self.map
-
-    def __getitem__(self, key):
-        return list(self)[key]
-
-    def add(self, key):
-        if key not in self.map:
-            end = self.end
-            curr = end[PREV]
-            curr[NEXT] = end[PREV] = self.map[key] = [key, curr, end]
-
-    def discard(self, key):
-        if key in self.map:
-            key, prev, next = self.map.pop(key)
-            prev[NEXT] = next
-            next[PREV] = prev
-
-    def __iter__(self):
-        end = self.end
-        curr = end[NEXT]
-        while curr is not end:
-            yield curr[KEY]
-            curr = curr[NEXT]
-
-    def __reversed__(self):
-        end = self.end
-        curr = end[PREV]
-        while curr is not end:
-            yield curr[KEY]
-            curr = curr[PREV]
-
-    def pop(self, last=True):
-        if not self:
-            raise KeyError('set is empty')
-        key = next(reversed(self)) if last else next(iter(self))
-        self.discard(key)
-        return key
-
-    def __repr__(self):
-        if not self:
-            return '%s()' % (self.__class__.__name__,)
-        return '%s(%r)' % (self.__class__.__name__, list(self))
-
-    def __eq__(self, other):
-        if isinstance(other, OrderedSet):
-            return len(self) == len(other) and list(self) == list(other)
-        return set(self) == set(other)
-
-    def __del__(self):
-        if all([KEY, PREV, NEXT]):
-            self.clear()                    # remove circular references
-
-if __name__ == '__main__':
-    print(OrderedSet('abracadaba'))
-    print(OrderedSet('simsalabim'))
diff --git a/thirdparty/oset/pyoset.py b/thirdparty/oset/pyoset.py
deleted file mode 100644
index 944d75c82..000000000
--- a/thirdparty/oset/pyoset.py
+++ /dev/null
@@ -1,83 +0,0 @@
-#!/usr/bin/env python2
-# -*- mode:python; tab-width: 2; coding: utf-8 -*-
-
-"""Partially backported python ABC classes"""
-
-from __future__ import absolute_import
-
-try:
-    from collections import MutableSet
-except ImportError:
-    # Running in Python <= 2.5
-    from ._abc import MutableSet
-
-
-KEY, PREV, NEXT = range(3)
-
-
-class OrderedSet(MutableSet):
-
-    def __init__(self, iterable=None):
-        self.end = end = []
-        end += [None, end, end]         # sentinel node for doubly linked list
-        self.map = {}                   # key --> [key, prev, next]
-        if iterable is not None:
-            self |= iterable
-
-    def __len__(self):
-        return len(self.map)
-
-    def __contains__(self, key):
-        return key in self.map
-
-    def __getitem__(self, key):
-        return list(self)[key]
-
-    def add(self, key):
-        if key not in self.map:
-            end = self.end
-            curr = end[PREV]
-            curr[NEXT] = end[PREV] = self.map[key] = [key, curr, end]
-
-    def discard(self, key):
-        if key in self.map:
-            key, prev, next = self.map.pop(key)
-            prev[NEXT] = next
-            next[PREV] = prev
-
-    def __iter__(self):
-        end = self.end
-        curr = end[NEXT]
-        while curr is not end:
-            yield curr[KEY]
-            curr = curr[NEXT]
-
-    def __reversed__(self):
-        end = self.end
-        curr = end[PREV]
-        while curr is not end:
-            yield curr[KEY]
-            curr = curr[PREV]
-
-    def pop(self, last=True):
-        if not self:
-            raise KeyError('set is empty')
-        key = next(reversed(self)) if last else next(iter(self))
-        self.discard(key)
-        return key
-
-    def __repr__(self):
-        if not self:
-            return '%s()' % (self.__class__.__name__,)
-        return '%s(%r)' % (self.__class__.__name__, list(self))
-
-    def __eq__(self, other):
-        if isinstance(other, OrderedSet):
-            return len(self) == len(other) and list(self) == list(other)
-        return set(self) == set(other)
-
-    def __del__(self):
-        if all([KEY, PREV, NEXT]):
-            self.clear()                    # remove circular references
-
-oset = OrderedSet