Fixes to disable MFQE when there is motion.
This patch includes: 1. fixes to disable block based termporal mixing when motion is detected (because this version of mfqe only handles zero motion). 2. The criterion used for determining whether to mix or not are changed to use squared differences rather than absolute differences. 3. Additional checks on color mismatch and excessive block flatness added. If the block as decoded has very low activity it is unlikely to yield benefits for mixing. Change-Id: I07331e5ab5ba64844c56e84b1a4b7de823eac6cb