Edited Unassigned: Auto-triggers on set, iset, map, and imap [151]

Currently, when one uses a set comprehension, Dafny doesn't automatically put a trigger on the corresponding existential. You can override this behavior with {:trigger}, but it would be nice if Dafny would use its auto-trigger mechanism in the absence of such an explicit trigger. It would also be nice if hovering over the keyword "set" in Visual Studio brought up a pop-up saying what triggers were used/rejected.

Also, ideally this feature would not just be for set, but also for iset, map, and imap.