Some work on the fancy user management

admin/ajax/creategroup.php

admin/ajax/createuser.php

admin/ajax/removegroup.php

admin/ajax/removeuser.php

admin/js/users.js

admin/templates/users.php

lib/Group/backend.php

lib/Group/database.php

lib/User/backend.php

lib/User/database.php

lib/app.php

lib/filestorage.php

lib/group.php

lib/user.php