Forward-port surface dithering from CM10.1

This allows the use of 16-bit color displays without excessive color
banding;

Change-Id: Icb469b9cb4beb686516c60bb576dbd0a73f505e0
Revert "Forward-port surface dithering from CM10.1"

This reverts commit 2589f36ced4c79c46aab7b9505d4038d0a2fe3db.

Conflicts:
	services/surfaceflinger/SurfaceFlinger.cpp
	services/surfaceflinger/SurfaceFlinger.h
Merge remote-tracking branch 'cm/cm-10.2' into cm-10.2

Conflicts:
	services/surfaceflinger/SurfaceFlinger.cpp
	services/surfaceflinger/SurfaceFlinger.h