framework: Custom lock screen background [1/2]

Patch Set 1:    * port the custom lock screen feature from
                  ics (http://review.cyanogenmod.org/#/c/16915)

                * thanks to Danny Baumann, who reworked the
                  framework part to work after Jelly Bean 4.2
                  lockscreen changes

Patch Set 2-3:  * remove obsolete files

Patch Set 4-7:  * revert XML changes

Patch Set 8,9:  * rebased

Patch Set 10:   * fix minor code style

Change-Id: I800506a9f9e001f659ee29b8b2dbe3464e5198f9
Lockscreen wallpaper setting

Change-Id: I649ad798642813aec91f696dd8887bd4d6e2b47d
SystemUI: awful hack until Google fixes MDP

History:
Google adds tripple buffering in 4.1 - works splendid
Google merges changes in qcoms HAL in 4.2.2 that will trash the
composition engine in fullscreen mode

Change-Id: I6bfbac30e6b04c027d404f8026a9533681bcd4e7
Merge remote-tracking branch 'pa/jellybean' into fjpa