Added ACL [NOT] matching, removed code duplication

-Added [NOT] option to ACL matches using the same tag system used by [regexp] matches.
-This allows ACL rules previously not possible or quite hard. Such as only showing buttons for users in a group (with multiple sets of groups-buttons)
-Refactoring to remove code duplication
-NOT rule also works in 'possible' settings for completeness (not as necessary in 'possible').