Bug 1109772 - Part 8: lift out Account interface.
Comment out live bookmarks test.
Flesh out Bookmarks.
WIP
Eliminate redundant favicon set.
Hiding MemoryBookmarkFolder. WIP.
WIP: use a factory to construct BookmarkModels.
Add a trivial ShareToDestination protocol.
Split out MemoryBookmarksSink from BookmarksModel.
Add a selectFolder convenience method for BookmarksModel.
Rename .model to .source, and break out onNewModel helper.
Handle folder selection.
Wire in in-memory sharing.
Eliminate redundant code, implement in-memory stub.
Shift old commented-out code into a working function (currently unused).
Rename internal 'root' to 'current' to avoid confusion.
Transparently include saved items in Mobile Bookmarks.
TESTING: getting access to the bookmarks UI again.