Forward-port surface dithering from CM10.2

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

Change-Id: Icb469b9cb4beb686516c60bb576dbd0a73f505e0

Test Plan: test and merge

Reviewers: synergy, anders3408, jriordan001, raymanfx, donald.munn, rlasalle15

Differential Revision: http://review.codefirex.com/D509