Run initialize() in test setUp() methods.
In Django 1.6, the test Client.login() method no longer uses a request, which

means that our middleware that loads the siteconfig isn't guaranteed to run.

For one of our tests, it was hitting the case that the user would be

authenticated against ModelBackend, and then when we tried to do an actual

request, it would load the siteconfig, replacing

settings.AUTHENTICATION_BACKENDS. Once this happened, it would check that

user.backend was in the loaded backends, and when it wasn't, set request.user

to be AnonymousUser.
I've solved this issue by calling initialize() inside TestCase.setUp(). A lot

of our TestCase subclasses weren't calling the super class' setUp(), so I've

fixed that.
This change isn't required on Django 1.5, but it is backwards compatible. I'm

submitting it now so we can get it in and reduce the size of the Django 1.6

patch.

Ran unit tests.