ITK: update ITK to 3.20

Utilities/ITK/CMake/CTestCustom.ctest.in

Utilities/ITK/CMake/InsightValgrind.supp

Utilities/ITK/CMake/itkTestFriendTemplatedFunction.cxx

Utilities/ITK/CMake/itkTestTemplatePartialSpecialization.cxx

Utilities/ITK/CMakeLists.txt

...es/ITK/Code/Algorithms/itkBayesianClassifierImageFilter.h

.../ITK/Code/Algorithms/itkBayesianClassifierImageFilter.txx

Utilities/ITK/Code/Algorithms/itkBinaryMedialNodeMetric.h

Utilities/ITK/Code/Algorithms/itkBinaryMedialNodeMetric.txx

Utilities/ITK/Code/Algorithms/itkBioGene.cxx

Utilities/ITK/Code/Algorithms/itkBioGene.h

Utilities/ITK/Code/Algorithms/itkBioGeneNetwork.cxx

Utilities/ITK/Code/Algorithms/itkBioGeneNetwork.h

Utilities/ITK/Code/Algorithms/itkClassifierBase.h

Utilities/ITK/Code/Algorithms/itkClassifierBase.txx

...Code/Algorithms/itkFFTComplexConjugateToRealImageFilter.h

Utilities/ITK/Code/Algorithms/itkFastMarchingImageFilter.txx

.../ITK/Code/Algorithms/itkImagePCADecompositionCalculator.h

...TK/Code/Algorithms/itkImagePCADecompositionCalculator.txx

...ITK/Code/Algorithms/itkKappaStatisticImageToImageMetric.h