Bug 734861 - Expose stylesheets, including UA, for a document via inIDOMUtils. r=bz

This patch adds an API to inspector utils that gets all stylesheets associated with a document, including UA sheets.
Bug 771865 - Avoid creating NumberObject in (.1).toString. r=luke
Bug 889876 - Make OS.Constants.Path.profileDir earlier. r=froydnj
Bug 895572 - Use the sandboxed tempDir so that modules/libmar tests can be run concurrently. r=bbondy
Bug 483446 - CSS3 'background-attachment: local' support. r=roc