Settings: allow device trees to invoke custom display settings

in this case gesture control settings.

Intent used: com.slim.action.LAUNCH_SCREEN_OFF_GESTURE_SETTINGS

Change-Id: I82f5a8a4075f109419b08014ad2d723bf2f54402

Conflicts:
	res/values/slim_strings.xml
	res/xml/display_settings.xml
	src/com/android/settings/DisplaySettings.java
Factory reset: Always show the "delete media" checkbox

CM is usually installed with recoveries that preserve datamedia,
including our own, so the assumption that deleting data will also
clear personal media is wrong. Always show the checkbox that was
originally limited to removable media to let the user do a full
reset

Change-Id: I2764c9509cc9ec50a1be979d748341037660a5da
(cherry picked from commit a07563b60adee75ff6594d15328c38190807f104)
(cherry picked from commit dfe4e8447abb84f5bf6995115b64a4b9e024016d)