Bug 868066 - Check to see if RequestDecode inside PrepareImage finished decoding the image and just draw it if so. r=dholbert, a=tef+

This is a quasi-backport of bug 799335.
Bug 868530 - Unique window identifier for identity on b2g device. r=jst, a=tef+
Bug 860571 - Pings for Firefox OS. r=ferjm, a=tef+
Bug 864575 - Notify all observers of file-changing at the right time. r=gyeh, a=lsblakk

When we receive multiple files in a row, we need to notify observers of
file-changing whenever a file is completely received. Currently we only
send one notification at the end of the entire session.
Bug 867482. r=bhackett, a=lsblakk
Bug 863241 - Part 1: Interface changes. r=vyang, a=leo+
Bug 863241 - Part 2: B2G MMS: the return items from getThreads should have type to identify mms or sms. r=vyang, a=leo+