QuickSettings : Add BatterySaver Tile (1/2)

Conflicts:
	core/java/com/android/internal/util/liquid/QSConstants.java
	packages/SystemUI/src/com/android/systemui/statusbar/phone/QuickSettingsController.java
BatterySaverTile: remove the on/off text
Credit: @Mahdi-Rom
Merge branch 'kitkat2' of https://github.com/LiquidSmooth/android_frameworks_base into kitkat2