Fix removal of backlight settings

Signed-off-by: Michael Bestas <mikeioannina@gmail.com>

Change-Id: I118e667b306a5a1e50d593f3f18828b7a921a511
Remake kb/button backlight controls as a PowerManager client

PM now has observers for these settings values and applies them in
realtime, so piggyback on those for button light management

Change-Id: I7568069bd6cacf5cbb56c8d0a1746894725b87fa

Conflicts:
	src/com/android/settings/cyanogenmod/BootReceiver.java
	src/com/crom/settings/fragments/ButtonBacklightBrightness.java
	src/com/crom/settings/fragments/KeyboardBacklightBrightness.java