Fixed @TransformationEstimationSVDScale@

Fixed inheritance issues which made @TransformationEstimationSVDScale@ never actually solve for scale. Did this by toggling on/off the use of pcl::umeyama, and fixing a few apparent incompatibilities in @TransformationEstimationSVDScale@. It appears the Umeyama method also allows us to solve for scale -- in my deadline crunch I didn't have time to test this, but if it also works, that will simplify the classes even more.