Removed the deprecated-since-1.2 "supports_object_permissions" and...

Removed the deprecated-since-1.2 "supports_object_permissions" and "supports_anonymous_user" flags on authentication backends.  If you have an authenication backend it now *must* suport these.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@16789 bcc190cf-cafb-0310-a4f2-bffc1f526a37