django-nose compatibility

I got obsessed by this and got it working! Still this is not necessarily a final pull request.

Nose is great with all its plugin support and usability and intuitiveness and flexibility, but it is a bit slower. That's not usually an issue, as tests should be written as fast as possible and nose used for its features.

Although this PR introduces nose compatibility, it does not add a requirement for it. It is completely compatible with the current runtests, so a new test case Just Works(tm).

The only bummer here is that it must be run against 
rest_framework.permissions.AllowAny (the default one) or it will break.

The test should probably be augmented anyway, so it doesn't behave differently based on configuration settings. I will append to this pull request if I see where to do that.

In the mean time, any comments are welcome, even if they are asking me to quit this ;)

**Note by @tomchristie**: Dropped 'RFD' from the issue title - non-obvious acronym.