Core / MotionEngine

 * PlanarResizer : right now, Resizer only resize to a sort of interlaced format, I need
a planar format.
 * Optimization in the resizers : no ASM optimizations right now, and I'm pretty sure
simple C optimizations can be achieved.
 * Better scene change detection : have to take the SAD into account
 * DifferenceFromNeighbour : as stated by violao, distance from median would be better
 * Use the Resizer in the pel interpolations.
  
Filters
 
 * Interpolaters : use exact interpolations.
 * MVMask : use the PlanarResizer
 * MVTracking : make it work
 * MVDenoise : make it be useful


