Enable Lockscreen Rotation
Add checkbox to enable/disable Lockscreen rotation in Settings

before: https://jira.cyanogenmod.org/secure/attachment/24824/Screenshot_2014-12-13-23-22-02.png

after: https://jira.cyanogenmod.org/secure/attachment/24825/Screenshot_2014-12-14-17-50-03.png

Change-Id: I5316021e2c7881d5725fb47e8123df5213aea89b