Settings : Port lockscreen shortcut configuration

Port lockscreen configuration from cm-10.2

Conflicts:
        res/values/cm_strings.xml

Change-Id: Ib4fd41f747912cc741eca1983c5f56df56176aad
Add back navigation ring customization.

Patchset 6 : Hide nav bar category on devices without nav bar

Change-Id: Iec29417ab65efc8df593508204b0981d5b193b74
Add back navigation bar customization.

Change-Id: I6431a611f3107fd1022df11362d1d2aa27b2f436