* Make `NullBooleanField` subclass `BooleanField`
This removes a lot of the redundancy that was in place becuase we
were not doing this. This maintains the `None` initial value that
was previously present, as well as disallowing `allow_null` to be
passed in.
* Remove special case for mapping `NullBooleanField`
In newer versions of Django, the `NullBooleanField` is handled the
same way as a `BooleanField(null=True)`. Given that we also support
that combination, and that our own `NullBooleanField` behaves in the
same manner, it makes sense to remove the special casing that exists
for it.
* Add test for BooleanField(null=True, choices)
* Remove special case for NullBooleanField
* Adjust mapping tests for NullBooleanField
* Fixed linting error
* Raise deprecation warning when NullBooleanField is used
* Fix linting issue in imports
* Fix ModelSerializer unique_together field sources
Updates ModelSerializer to check for serializer fields that map to the
model field sources in the unique_together lists.
* Ensure field name ordering consistency
* SearchFilter to support Custom query Transforms
Since Some fields support `__` as a custom Transform for query lookups we needed to update the m2m checking code to handle search_fields that contain __ that are not relationships.
* Update documentation on SearchFilter to include references to JSON and HStore Fields.
Previously it was only mapping the `type` and `format`, even though
for some field types (like a `MultipleChoiceField`) we map more
than just these. And for some fields (like a `ChoiceField`) we do
not map the `type` at all.
* serializers: removes no longer needed compat checks
UUIDField and DurationField are both supported in all supported Django
versions.
IPAddressField was removed in Django 1.9, which is no longer supported.
* serializers: move related code closer together
This way it's easier to see all of the mappings in one place.
* serializers,docs: remove some DRF 2.x references
The last release of DRF 2.x was 5 years ago, it seems fine to remove
these references now.
* Version 3.11
* Added notes on OpenAPI changes for 3.11.
* Minor docs tweaking
* Update package version and supported versions
* Use a lazy import for django.test.client.encode_mutlipart. Closes#7078
