systemui: Forward-port notification counters

 * Port from CM11

Change-Id: Id9d0954acffd00bdb470b9eccbdb3b45fbd995c1

Conflicts:
	core/java/android/provider/Settings.java
	packages/SettingsProvider/res/values/defaults.xml
	packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java