* New probs for subpel filters/tx_count
* Makes a change to not reset to defaults for the tx_size
probs if an intermediate frame reverts to using a fixed tx_size.
* A few updates to the parameters for backward adaptation for mode/mv
* some cosmetic cleanups

derf300: +0.06%

Change-Id: I22994d659bc31ca7a4fc8820fde24001e64a2920