settings: Make mobile settings switch

 * Nobody likes carriers, but let's not bury these settings behind
   10 layers of indirection. Many users (like me) who travel often
   will need to access these options frequently.
 * The top level switch disables mobile data.

Change-Id: I1bd4d1116a2c73832230d66c94df2c3c0aacf698

Conflicts:
	src/com/android/settings/Settings.java

Conflicts:
	res/xml/settings_headers.xml
	src/com/android/settings/Settings.java

Conflicts:

	src/com/android/settings/Settings.java
settings: Enable location mode header switch

Change-Id: I347e769351bc15daa87d3b6d684afe4e80416ecc
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>

Conflicts:
	src/com/android/settings/Settings.java
	src/com/android/settings/location/LocationSettingsBase.java

Conflicts:
	src/com/android/settings/Settings.java

Conflicts:

	src/com/android/settings/Settings.java