DeskClock: Add back flip and shake actions

Cherry-picked and ported from:
 * http://review.cyanogenmod.org/#/c/29894/



Signed-off-by: Jorge Ruesga <jorge@ruesga.com>

Conflicts:
	res/xml/settings.xml
	src/com/android/deskclock/SettingsActivity.java
	src/com/android/deskclock/alarms/AlarmService.java

CRs-Fixed: 1014635

Change-Id: I9be82187559ccd483b8e4da068890f532e60b8f7