systemui: Forward-port notification counters

 * Port from CM11

Change-Id: Id9d0954acffd00bdb470b9eccbdb3b45fbd995c1

Conflicts:
	packages/SettingsProvider/res/values/defaults.xml
	packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java
	packages/SystemUI/res/drawable-hdpi/ic_notification_overlay.9.png
	packages/SystemUI/res/drawable-mdpi/ic_notification_overlay.9.png
	packages/SystemUI/res/drawable-xhdpi/ic_notification_overlay.9.png
	packages/SystemUI/res/drawable-xxhdpi/ic_notification_overlay.9.png