need to check in 355663 and 356023 before anything else; 356023 is very likely to break Composer, that's normal.
WANTED ! I need more peer reviewers for Composer... I just cannot put everything on Neil's and timeless's shoulders, that's impossible. If you have spare cycles and are willing to help reviewing XUL, JS, XBL and CSS, please add a comment to this post with your bugmail address so I can send you requests. Thanks!
9-11 may-2012, CSS WG meeting, Hamburg, Germany
29 oct-2 nov 2012, W3C Technical Plenary Meeting, Lyon, France