debug mode will not get site menu from session, and will not save menu to session.
app module no need perform permission check when render site menu.
add has_model_perm method.
display an tip when user does't has any model change permission.
move acl plugin to auth plugin.
perform dashboard widget permission check while init widget.
do widget permission check.
do models permission check.
merge acl plugin and add user_can_access_owned_objects_only plgin.
display error msg when show object detail page.
i18n main dashboard title.
add xadmin.py, add user settings model admin.