[1/2] Base: Toggle lock screen camera widget

Adds an option to enable/disable camera widget on lockscreen.

Settings: https://gerrit.omnirom.org/#/c/4702/

Change-Id: Ia2ccdd306956cddd8285c30ccceb759dff406366
[1/2] Base: Hide power menu on lockscreen

Adds an option to enable/disable power menu on lockscreen.

Settings: https://gerrit.omnirom.org/#/c/4702/

Change-Id: I0de1501d0ecedb7b9b08fbb3aebaecd0e63cc09e
[1/2] Base: Lockscreen blur

Show the content behind lockscreen, blurred.

Settings: https://gerrit.omnirom.org/#/c/4702/

Change-Id: I0d7ee20d6b415567f0051d716ba0db2e55511e91
Merge "[1/2] Base: Toggle lock screen camera widget" into android-4.4
Merge "[1/2] Base: Hide power menu on lockscreen" into android-4.4
Merge "[1/2] Base: Lockscreen blur" into android-4.4
Merge remote-tracking branch 'omni/android-4.4' into android-4.4