This allows to match and transfer data between two meshes with similar shape but complete arbitrary different transform.
Note that the result will be best if the meshes (more precisely, their vertices) are exact copies of each other.
Otherwise, method used can only perform an approximated best match, which means you'll likely get better
results if you 'visually' make them match in 3D space (and use 'Object Transform') instead.
Titles says everything, just two notes:
* We have to actually transfer plain *normals*, not 'compressed' clnors,
so had to add pre/post process to transfer to make the conversions.
* Also added interpolation and advanced copy/mixing to CD_NORMAL, for same reasons.
Campbell Barton
Bastien Montagne