mozilla/fireplace — pull request #60 by ednapiranha (2013-03-19 16:04:31+00:00)
Title: use makeOrGetOverlay 

So I just realized there was a helper for creating this overlay but it requires z.body not z.container. Wanna merge or is this just not a good idea and we should copy pasta similar functionality whenever we need overlay support? (I'm thinking the former)