Settings: Forward port long-press-back to kill app (1/2)

Change-Id: I60f4b95eb9cc2ef6cf73a5f9317bca066e6bb901

Conflicts:
	res/values/cm_strings.xml
	src/com/android/settings/DevelopmentSettings.java

	modified:   res/xml/development_prefs.xml
	modified:   src/com/android/settings/DevelopmentSettings.java