[DEV-1152] Substitute get_user_model method for hardcoded User in create_user.
[DEV-1152] Changes mentions of User to AuthUser in akbot_user code. Mend __setattr__, allowing it to set attributes on AskbotUser. Format docstrings.
[DEV-1152] Re-indent __all__ in models/__init__.py to keep diff minimal.
[DEV-1152] Move User import and followit code back to top of models/__init__.py to minimize diff.
[DEV-1152] Re-enable signals in createsuperuser.py.
[DEV-1152] Add comment to save() method of AskbotUser.
[DEV-1152] Add comment to try-except in __setattr__.
[DEV-1152] Change save in User post_save handler to use AskbotUser superclass method to avoid more User save signals being sent.
[DEV-1152] Replace self.user in __setattr__ with get_user_model. Explicitly raise AttributeError in __getattr__.