Fixing tests for Python3.

CMake/vtkTestDriver.py

Common/DataModel/Testing/Python/TestNumericArrayImageData.py

Common/DataModel/Testing/Python/TestTemplates.py

Filters/Core/Testing/Python/TestContourCases.py

Filters/Core/Testing/Python/fieldToPolyData.py

Filters/Core/Testing/Python/fieldToRGrid.py

Filters/Core/Testing/Python/fieldToSGrid.py

Filters/Core/Testing/Python/fieldToUGrid.py

Filters/General/Testing/Python/tableBasedClip.py

Filters/Geometry/Testing/Python/TestGhostPoints.py

Filters/Geometry/Testing/Python/geomFilter.py

Filters/Geometry/Testing/Python/structuredGridBlanking.py

Filters/Hybrid/Testing/Python/TestProcrustesRigidCentroid.py

Filters/Modeling/Testing/Python/Hyper.py

Filters/Modeling/Testing/Python/TestSpherePuzzleArrows.py

Filters/Verdict/Testing/Python/MeshQuality.py

IO/Core/Testing/Python/TestGlobFileNames.py

IO/Core/Testing/Python/TestSortFileNames.py

IO/Exodus/Testing/Python/TestExodusPolyhedra.py

IO/Exodus/Testing/Python/TestExodusWithNaN.py