Workaround for no Cell Location Updates When Display Off
https://code.google.com/p/android/issues/detail?id=10931

Conflicts:
	res/xml/preferences.xml
	src/org/mozilla/mozstumbler/cellscanner/CellScanner.java
	src/org/mozilla/mozstumbler/cellscanner/GeminiCellScanner.java
	src/org/mozilla/mozstumbler/preferences/Prefs.java