Add Power Menu Tile

Click once: Brings up Power Menu.

Long click: Will let you reboot your device.

Ported from:

Rascarlo's (https://github.com/rascarlo/platform_frameworks_base/commit/d9dbc4f6f9bb78683c21f8d28fb35c54cfe323b1)
CyanogenMod (http://review.cyanogenmod.org/#/c/30502/)