Dont swallow errors in callable sources

Fix UniqueTogetherValidator for NULL values

List resource not updated between requests

Formally upgrade suport to Django 1.8-beta

Disable select field if no choices available

adding django-rest-auth to Third Part Resources and Authentication

Remove duplicated code in routers.SimpleRouter

Fix url_path on dynamic routes for inherited viewsets. Fix #2583

SimpleRouter.get_routes was popping out the url_path kwarg from
list_route and detail_route decorators. This was causing troubles
when the route was re-used, for example if the viewset was
inherited.

Set field max_length/max_value as actual attribute.

updated outdated link at testing.md#APIClient

max_value and min_value are not in kwargs

Check if sessions are enabled before calling logout.

The SimpleMetadata class in metadata.py tries to getattr() attributes
on a field. For this to work, max_length and min_length have to be
actually set as an attribute.
Did the same for min_value and max_value and added those two to
SimpleMetadata.get_field_info

Fixes HiddenField being rendered in HTMLFormRenderer