Undo last previous action button

[Buckminsterfullerene02]

If you make an action such as mod or profile deletion by accident and you don't know what it was you deleted (as mentioned in #78), it would be nice to have an emergency "oh shit go back" button.

I'm sure this would rely on #13 to be robust...

... but since the only good action I can think of that this is useful for is profile or mod deletion, maybe some shitter, bodge solution with a temp value of whatever it was that was deleted being stored for the undo button would be good enough.

[trumank]

An undo stack would be a pretty good solution for the time being and should be fairly easy to implement for most profile modification made in the GUI. The only difficult one that comes to mind is undoing something that is no longer present in the mod cache, though maybe cache changes should just invalidate the history.