Moved all "menus" tests inside a proper package.
Improved style for radio buttons.
ImFixed RTL style for radio buttons.
Added proxy "ModelBackend" with some changes.

NOTE: It'll  now return "True" when a check on a per-object basis is invoked and the user has an associated model-level perm (Django's default: False).
Added tests for "menus.templatetags.menus.render_menu".
Added tests for "menus.templatetags.menus.render_user_bookmarks".