Merge pull request #114 from ixc/master

Fixed custom User compatibility in Django 1.5, preventing circular imports.
Better pyflakes
Updated setup.py params
Started integration tests for custom User model
Started merging performance branch
Merged example into performance
All tests passes for Django 1.5
Tox conf update, better decorator tests
There was wrong version for direct fk marked as being new
Remove comments
Updated docs (custom user model warning)
Fixed imports
Updated url to Django 1.5 RC at tox for Python 2.6 env
Python 3 support. Fixes #115
Fixed migrations to run from scratch on projects with a custom User model.