[vtkusers] Changes to vtkExtractCTHPart

[Berk Geveci]

Hi folks,

I just changed vtkExtractCTHPart (in cvs vtk) such that it produces 1
vtkMultiBlockDataSet instead of 1 output per part. Using it now
requires setting vtkCompositeDataPipeline as the default executive and
also a composite data sink such as vtkMultiGroupPolyDataMapper. Look
at VTK/Parallel/Testing/Tcl/TestExtractCTHPart.tcl for an example.

-- 
 Berk Geveci
 Kitware Inc.
 28 Corporate Drive
 Clifton Park, NY, 12065