ENH : ENTROPY FUNCTOR added

Code/BasicFilters/otbFunctionWithNeighborhoodToImageFilter.h

...BasicFilters/otbFunctionWithNeighborhoodToImageFilter.txx

...Common/otbUnaryFunctorNeighborhoodWithOffsetImageFilter.h

...mmon/otbUnaryFunctorNeighborhoodWithOffsetImageFilter.txx

Code/FeatureExtraction/otbEnergyTextureFunctor.h

Code/FeatureExtraction/otbEntropyTextureFunctor.h

Testing/Code/FeatureExtraction/CMakeLists.txt

Testing/Code/FeatureExtraction/otbEntropyTextureFunctor.cxx

...ng/Code/FeatureExtraction/otbFeatureExtractionTests11.cxx