Status bar brightness control

+ added some fixes to original implementation (thanks mostly cm for that)
+ add multiuser support

Change-Id: Ibc5cc15a9b43eade73670d308d5cc788c93b6210

Conflicts:
	core/java/android/provider/Settings.java
Merge branch 'kitkat-remix' of github.com:AOSPAL/android_frameworks_base into kitkat-remix