Add SSE versions of all Repair modes
Mare Repair and Removegrain work correctly on non-mod16 clips
Validate Repair parameters

Also fix formatting of Removegrain constructor
Make repair use appropriate modes for chroma planes
Move some common stuff to common.h
Fix Clense producing incorrect result on last and second to last frame

Reported by Myrsloik
Allow mixing different colorspaces when chroma is not processed in Repair
Make ForwardClense and BackwardClense identical to original implementation