Bug 871510 - Some event handlers appear as undefined, hiding the appropriate null values in the prototype; r=msucan
Bug 873065 - Use DEVICESTORAGE_SDCARD for unknown file types. r=dhylands

The method DeviceStorageFile::CreateUnique fails for files with an
unknown extension. It calls DeviceStorageFileChecker::GetTypeFromFileName
to retrieve the default location. The returned value is "Unknown", which
is passed to the constructor of DeviceStorageFile. This class doesn't
handle "Unknown" in it's initialization, and fails without creating a
file.

This patch changes the default return value of GetTypeFromFileName to the
constant DEVICESTORAGE_SDCARD. All files with unknown extension will now
be stored on the sd card.
Bug 872800 - Remove extraneous printfs added from Bug 858416. r=mchen
Bug 872800 - Fix volume availability notifications for composite storage areas. r=mchen
Bug 872170 - Fix camera file saving with composite device storage. r=mikeh
Backout changeset 000ed86d069f (bug 861117) which caused bug 871560

--HG--
extra : rebase_source : 6359c671885b93f7885ca2cabfd8da772692d548
Bug 873216 - Fixed a typo in `./mach help`; r=gps

DONTBUILD (NPOTB)
Merge the last PGO-green inbound changeset to m-c.
Merge m-c to birch.
Merge m-c to fx-team.
Merge birch to m-c.
Merge fx-team to m-c.
Merge inbound to m-c.
Merge m-c to inbound.