Storage configuration options (1/2)

This allows the user to change the default storage path from
the standard internal storage to any available external storage.

When the path is changed, it sends an intent to the gallery
application to keep the paths in sync (Requires part 2 in Gallery2)

Change-Id: I1dbd1161230ad1d48440c6c3a29841c5c486a905
Merge "Storage configuration options (1/2)" into cm-11.0