vtkPVPlaneCutter subclasses vtkPlaneCutter to support vtkOverlappingAMR/vtkHyperTreeGrid
by delegating to the appropriate amr/hyper-tree-grid plane cutters.
vtkPVCutter is now using vtkPVPlaneCutter internally whenever possible,
but not for vtkOverlappingAMR because it's not composite dataset aware yet.