Redundant functionality in FieldConvert
after merging !903 (merged) we have at least two modules which provide redundant functionality: ProcessScaleInFld, which scales a field and the cp option of ProcessInterpPoints. there might be more, though, depending on where one draws the line for redundancy. Do we want to remove those or keep them for the sake of backwards compatibility? If we were to remove them, 5.0 might be a good opportunity.