fix a number of warnings on 32bit vtkIdType

Common/Core/vtkArrayCoordinates.cxx

Common/Core/vtkArrayExtents.cxx

Common/Core/vtkArrayExtentsList.cxx

Common/Core/vtkArraySort.cxx

Common/Core/vtkUnicodeStringArray.cxx

Common/DataModel/vtkGenericEdgeTable.cxx

Common/DataModel/vtkGraph.cxx

Common/DataModel/vtkHyperOctree.cxx

Common/DataModel/vtkIncrementalOctreePointLocator.cxx

Common/DataModel/vtkKdTree.cxx

Common/DataModel/vtkOctreePointLocator.cxx

Common/DataModel/vtkReebGraph.cxx

Filters/Core/vtkDataObjectGenerator.cxx

Filters/General/vtkAreaContourSpectrumFilter.cxx

Filters/General/vtkClipClosedSurface.cxx

Filters/General/vtkContourTriangulator.cxx

Filters/General/vtkMergeCells.cxx

Filters/General/vtkTemporalPathLineFilter.cxx

Filters/General/vtkVolumeContourSpectrumFilter.cxx

Filters/Geometry/vtkGeometryFilter.cxx