Halo: Add master switch to disable Halo (2/2)

Originally Authored by : Der-Schubi

Conflicts:
	res/values/strings.xml
	res/xml/halo_settings.xml
	src/com/android/settings/paranoid/Halo.java

Conflicts:
	res/values/strings.xml
	res/xml/halo_settings.xml
	src/com/android/settings/paranoid/Halo.java