HeadsUp: Add heads up quicksettings tile. (1/2)

Change-Id: Ibc6ffffb48ac1831ee5fe398577023960e0e79d4

Conflicts:

	core/java/com/android/internal/util/cm/QSConstants.java
	packages/SystemUI/res/values/purity_strings.xml
	packages/SystemUI/src/com/android/systemui/statusbar/phone/QuickSettingsController.java