Add option to always show battery status on lockscreen (2/2)

Based on the feature by burnsra in CM7

Authored by blunden
Tweaked by dvtonder

Screenshot: https://dl.dropbox.com/u/50993944/Screenshot_2012-08-03-08-47-16.png

Patchset 1  : Initial commit
Patchset 2  : UI redesign
Patchset 3  : Patch description text updated
Patchset 4  : Fix derp in comments

Change-Id: I1c8c8eef3d0c913c621f735e7d5e395c8768fe76

Conflicts:
	res/values/arrays.xml
	res/values/strings.xml
	res/xml/lockscreen_interface_settings.xml
	src/com/android/settings/cyanogenmod/LockscreenInterface.java