Bug 1042319 - [Gallery] Update gallery edit UI r=djf

It would be nice to have a more decoupled way to do this, but I don't have anything to suggest.  I suppose you're testing for enableSaveAndApplyButtons so that the ImageEditor class could work even without the  code around it?

What happens when we crop images for the pick activity. Does that end up calling enableSaveAndApply?  Is it harmless?