rework immersive mode => immersive desktop

add ability to show only the navbar to immersive style
add expanded desktop to disable swipe to show UI gestures
add new low profile mode to dim the UI within an app

PS2: fix statusbar being a bonehead and not observing expanded desktop in style 2
PS3: clean up some code and revise lights out layout for clock views

Change-Id: If69aed7297eebe4d12934751f7be55f896c727d9