Add hardware keys support

Squashed commit from CM and Davor
Move Hardware back to kill to hardware keys

Change-Id: Idabc1610284622f661dfebd7633f9afef74ad7c7

Use AOKP overflow menu option as default

Change-Id: Ie81a625b994d18e2cc3ea72038b08eb84e0bd7c6

Rework Hardware keys and add double button settings - CM

Change-Id: Id6d6bcdb95c5b6483dabd8880fce456ef51632cb

Move Hardware keys to main RC menu

Change-Id: I04627b90fa928d0ad522c00f0a11440fe94364eb

Conflicts:
	res/xml/preference_headers.xml

Move hardware back to kill to hw keys

Change-Id: I02ca095e44ad13aac3848b2ff4d199428c344537

Change-Id: Idabc1610284622f661dfebd7633f9afef74ad7c7

Conflicts:
	res/values/arrays.xml
	res/values/strings.xml

Add missing strings