Adds ability to answer call with hardware HOME button (preparation to winter time)

Patch set 1 : Upload the change
Patch set 2 : Only change the real Author
Patch set 3 : Bugfix:
              Add register for the ContentObserver (Settings.Secure.RING_HOME_BUTTON_BEHAVIOR) in PhoneWindowManager,
              and correcting the logging functions and deleting some unneeded comments
Patch set 4 : Rebased

Change-Id: Ia2aba658ca628232d8e283219950528b60eced4a
Frameworks: apple can do...we can do as well

incredible apple engineers speeded up the overall UI and reduced per default slightly
the animation scales. Well we do as well and reduce it from 1 to 0.75...smooth, looks well
and does not break anything

Change-Id: Icbcc889e49c8d3ab24cf2b1c10bbe0e8bf7e7637