finetune bit/distortion weighting factor used in motion estimation, the old coeffs where finetuned relative to incorrect mv_penalty tables which where then fixed later but the coeffs where not
this _may_ fix the long standing blocking artifacts, but may also introduce mudding artefacts theoretically, so please tell us if u stumble across any so we can either fix them or export this variable so the user can change it


git-svn-id: file:///var/local/repositories/ffmpeg/trunk@3189 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b