ENH: additional options for transformPoints and surfaceRefineRedGreen

- add -recentre option to shift points according to the bounding box
  centre before performing other operations

- add -auto-origin to use the bounding box centre as the origin for
  rotations. Has lower priority than the -origin option.

- surfaceTransformPoints now has distinct -read-scale, -write-scale
  options (as per surfaceMeshConvert). Silently accepts -scale as
  equivalent to -write-scale, for backwards compatibility and
  similarity with transformPoints

- add -steps option for surfaceRefineRedGreen for successive
  refinement