* Much, much faster
* Remove message length pass and lots of other useless code
* Create pseudo-attachment for long messages (click to download) that
includes size (so user can determine whether it's worth it)
* Handle download of message via pseudo-attachment; real attachments
are then created as necessary.
TODO: Add real UI with UX input (or modify existing to clean up the
loose ends)
TODO: Optimizations for loading the whole message
TODO: Get server delete working (isn't working currently anyway)
Change-Id: I31f3809fc5a2f9fd490d33cfed70d2930654e71d
f6db592c31