framework: Add compass tile (1/2)

Add a compass tile to quick settings.
Clicking on it enables the sensor and clicking again disables it.

Screenshot: http://goo.gl/2frdpy

Change-Id: Icd9d12929f0491f6958f30de139ef39bb4c2e037

Conflicts:
	core/java/com/android/internal/util/cm/QSConstants.java
	packages/SystemUI/res/drawable-hdpi/ic_qs_compass_off.png
	packages/SystemUI/res/drawable-hdpi/ic_qs_compass_on.png
	packages/SystemUI/res/drawable-mdpi/ic_qs_compass_off.png
	packages/SystemUI/res/drawable-mdpi/ic_qs_compass_on.png
	packages/SystemUI/res/drawable-xhdpi/ic_qs_compass_off.png
	packages/SystemUI/res/drawable-xhdpi/ic_qs_compass_on.png
	packages/SystemUI/res/drawable-xxhdpi/ic_qs_compass_off.png
	packages/SystemUI/res/drawable-xxhdpi/ic_qs_compass_on.png
	packages/SystemUI/res/values/cm_strings.xml
	packages/SystemUI/src/com/android/systemui/quicksettings/CompassTile.java
	packages/SystemUI/src/com/android/systemui/statusbar/phone/QuickSettingsController.java
Don't cleanup overlay mapping for non-theme apps

mOverlay structure should keep all app/theme mappings even
if the app does not exist. Otherwise we will have to insert back the mapping
for every app that is installed which would be time consuming.

Without this patch an upgrade app loses its applied theme
until the device is rebooted.

Change-Id: Id02b8e0a3bdd78d1a9d39cd38294c584ef95f8db