Containers - add ability to have a container item only show in pages that do not match the URL pattern

Currently, container items can match an exact url but it's not easy to NOT get them to show on everything except a certain page. Therefore, an option to say, match everything EXCEPT a certain url would be handy.

I know I could go through and add container items for each parent url, avoiding the page I didn't want the item to be visible on and have it show up on all the others but at the time I was working on a fairly expansive site and the length of time it would have taken to add all those container items was prohibitive.