Add battery level text to status bar (1/2)

1. Add TextView to display battery level percentage next to the battery
icon.
2. Remove support for displaying battery percentage on the actual
battery icon itself.
3. Also respect view on lockscreen and opened notification drawer.

Change-Id: Iab6228f5316908961c8647773bd3c8655df29679

Conflicts:
	packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java
	packages/SystemUI/src/com/android/systemui/BatteryMeterView.java