Bug 873400: Fix destination directory for Bluetooth file transfers, r=echou

Bluetooth file transfers store the file in 'downloads/bluetooth'. This
patch changes the location to 'Download/Bluetooth' for consistency with
other sub-systems.
Bug 853235 - Combine pairing-related system messages into one type, r=echou
Bug 868952 - Fix the getAll(...) function in AlarmDB to be more efficient. r=clian
Bug 870682 - [gonk-jb-4.2] Add basic support for audio control API. r=mwu
Merge m-c to birch.