Settings: Option to enable/disable scrolling cache

Conflicts:
	res/values/cr_arrays.xml
	res/values/cr_strings.xml
	res/xml/development_prefs.xml
	src/com/android/settings/DevelopmentSettings.java

Change-Id: I57e63e48e3aa4be7a978d6d71979b5c82c960459
derp

Change-Id: If945af0bd06f841594e2d5c72e78da35673523de