add option to force high-end graphics on low memory devices

Change-Id: I34e0d7381615485b58385abed743e01f7272772d
Allow changing screen-off animation (2/2)

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

Change-Id: I5ebfab22e68ea34e3babfaacd9c8103e25932d3d