ENH : improve Mean Shift : add cluster (work in progress)

Code/BasicFilters/otbMeanShiftImageFilter.h

Code/BasicFilters/otbMeanShiftImageFilter.txx

Code/BasicFilters/otbMeanShiftImageFilterBase.h

Code/BasicFilters/otbMeanShiftImageFilterBase.txx

Code/BasicFilters/otbMeanShiftVectorImageFilter.h

Code/BasicFilters/otbMeanShiftVectorImageFilter.txx

Testing/Code/BasicFilters/CMakeLists.txt

Testing/Code/BasicFilters/otbBasicFiltersTests9.cxx

Testing/Code/BasicFilters/otbMeanShiftImageFilter.cxx

Testing/Code/BasicFilters/otbMeanShiftVectorImageCluster.cxx

Testing/Code/BasicFilters/otbMeanShiftVectorImageFilter.cxx

...ng/Code/BasicFilters/otbMeanShiftVectorImageFilterNew.cxx