Added rules support

Reduced page size in administration interface and made compatible with version 6.x-1.0-beta4 (disappearing avatars)

* uninstall hook complete
* no user associated to submitted avatars #746878
* email text now customizable
* fixed form error on disapproved avatar upload

* Private filesystem should now work ok
* When deleted from admin, avatar files are erased from disk again
* Changed menu voices to be more appropriate
* Now, the module does not mess things up when the user form submit with errors (for instance: passwords not matching)

NEW FEATURES
* Send a reminder to moderators: by email or when they login