VTK to VTK-m convert now support mixed triangle/quad polydata
requested to merge robertmaynard/vtk:vtkm_polydataconverter_support_mixed_polycell_types into master
Corrects the following failing tests:
VTK::AcceleratorsVTKmFiltersCxx-TestVTKMCoordinateSystemTransform
VTK::AcceleratorsVTKmFiltersCxx-TestVTKMHistogram
VTK::AcceleratorsVTKmFiltersCxx-TestVTKMNDHistogram