Allow changing screen-on/off animations (2/2)

* Allow enabling screen-on & off animation
* Allow selection between fade & crt effects if the device allows it

Change-Id: I5ebfab22e68ea34e3babfaacd9c8103e25932d3d

Conflicts:
	res/values/cm_strings.xml

	modified:   res/values/cm_strings.xml
	modified:   res/xml/display_settings.xml
	modified:   src/com/android/settings/DisplaySettings.java