Custom anonymous user username.

The first anonymous user created needs a configurable value
since django 1.5 supports custom user modules.
Django 1.5 foreign key dependency

Also make sure that code doesn't call compat.py twice.
This ensures there's no circular dependencies.
Fixed Django 1.5 custom User model support to prevent circular imports.

All tests pass, and if the tests are run within a project with a custom
User model, they will also pass after the permission names in the tests
are modified to use the custom model, and the fixtures are similarly
adjusted.
Fix test failures whne ran in projects that register the ContentType admin.
Updated AUTHORS to add myself, as requested.
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.