Lock Screen - Add Lockscreen Wallpaper (2/2)

PS3 add Default Wallpaper as option

PS4 fix preference list doesnt show selected item

PS7:
Rebased and modified to check for existence of a lock screen
wallpaper when updating the preference.

Change-Id: I2f4db0ddc132482d191eea4f76160b51b4063a60

Conflicts:
	res/values/vendor_arrays.xml
	res/values/vendor_strings.xml
	res/xml/lockscreen_interface_settings.xml
	src/com/android/settings/chameleonos/LockscreenInterface.java
Add gesture based lockscreen security. [2/2]

PS2:
Tidy things up a bit.

Change-Id: I83e3ab643e19b2a2d9c8416f4925bbab05bbc896

Conflicts:
	src/com/android/settings/SecuritySettings.java
Add isValidFragment to various lock settings

Change-Id: Ia79fd5e3c9f829b919c5f8f9abf6ecc606434f18
Allow using a gesture lock when adding users.

Change-Id: I20e2d09b98fa174ad47d96f206332794001c22b9
Fix some derps
Fix background option