* Update the http signature auth library ref link
It seems that the djangorestframework-httpsignature package is outdated
and there is updated fork named drf-httpsig.
* Fixing the link ref format in the http signature section
* Update assertion style in user logout test
* Apply middlewares to django request object
* Fix test for request auth hiding AttributeErrors
* Re-raise/wrap auth attribute errors
* Fix test for py2k
* Add docs for WrappedAttributeError
As per [their blog post of the 27th April](https://blog.readthedocs.com/securing-subdomains/) ‘Securing subdomains’:
> Starting today, Read the Docs will start hosting projects from subdomains on the domain readthedocs.io, instead of on readthedocs.org. This change addresses some security concerns around site cookies while hosting user generated data on the same domain as our dashboard.
Test Plan: Manually visited all the links I’ve modified.
This allows subclassing TokenAuthentication and setting custom keyword,
thus allowing the Authorization header to be for example:
Bearer 956e252a-513c-48c5-92dd-bfddc364e812
It doesn't change the behavior of TokenAuthentication itself,
it simply allows to reuse the logic of TokenAuthentication without
the need of copy pasting the class and changing one hardcoded string.
Related: #4080
Based on the [new documentation](https://docs.djangoproject.com/en/dev/topics/auth/customizing/#django.contrib.auth.get_user_model) for Django 1.7 we should now use:
```python
@receiver(post_save, sender=settings.AUTH_USER_MODEL)
```
instead of:
```python
@receiver(post_save, sender=get_user_model())
```
because `get_user_model()` only works once Django has imported all models. Otherwise you'll get:
```python
django.core.exceptions.AppRegistryNotReady: Models aren't loaded yet.
```
When trying to start your sever after adding token authentication.
From the Docs, ( linked above as well ) :
>New in Django 1.7:
>When connecting to signals sent by the User model, you should specify the custom model using the AUTH_USER_MODEL setting.
