Ringlock (1/3): Style options added to CM settings

This patch combines the two concurent lockscreen designs in an option:
http://review.cyanogenmod.com/8564 - http://review.cyanogenmod.com/8674
credits to Stefano Pignataro for the first and Prash for the second redesign

this patch also can be used to add even more styles in the future - if provied.
this patch also cleans up some coding.

Background Info: Lockscreen cannot be themed - so this is the only way except
tempering with framework-res.apk

Change-Id: I055fb5f1c760656c3b1f750543cc6f054ee30fbe