Fix test for #154.
Handle only/defer manager methods (close #166).
Handle non-translation form submision for translated models (close #167).
Update docs about loaddata command new keyword.
Fix Django 1.5 metaclass retrieval (ref #166).
Fix test running in Django 1.6: boolean field default.
Fix test running in Django 1.6: model opts function caching.
Fix test running in Django 1.6: foreignkey support (close #169).
Optimize testrunner.

Since LANGUAGES setting is overridden in tests, there is no need
to use them all in pre-test database creation (because database
would be rebuild anyway and only time is wasted).
Remove dead code from tests.
Fix broken docs link.
Update docs example.
Use proper assert* methods in test.

This remove PendingDeprecationWarnings.
Added convenience admin classes for easier inclusion of tabbed translation fields static files (closes #171).
Added docs for tabbed translation fields admin classes.
Fixed wrong use of inline literal.
Fixed typo and made a small reword.
Fix _mt_init attribute deletion (close #176).
Initial work towards python 3 support
Fixed flake8 complaints.