Merging feature Classifier quality index (Jira 847) into develop

...Applications/AppClassification/app/otbImageClassifier.cxx

...les/Applications/AppClassification/app/otbTrainLibSVM.cxx

Modules/Applications/AppClassification/test/CMakeLists.txt

Modules/Learning/SVMLearning/include/otbSVMModel.h

Modules/Learning/SVMLearning/include/otbSVMModel.txx

...earning/Supervised/include/otbBoostMachineLearningModel.h

...rning/Supervised/include/otbBoostMachineLearningModel.txx

.../Supervised/include/otbDecisionTreeMachineLearningModel.h

...upervised/include/otbDecisionTreeMachineLearningModel.txx

...ised/include/otbGradientBoostedTreeMachineLearningModel.h

...ed/include/otbGradientBoostedTreeMachineLearningModel.txx

...earning/Supervised/include/otbImageClassificationFilter.h

...rning/Supervised/include/otbImageClassificationFilter.txx

...rvised/include/otbKNearestNeighborsMachineLearningModel.h

...ised/include/otbKNearestNeighborsMachineLearningModel.txx

...arning/Supervised/include/otbLibSVMMachineLearningModel.h

...ning/Supervised/include/otbLibSVMMachineLearningModel.txx

...les/Learning/Supervised/include/otbMachineLearningModel.h

...s/Learning/Supervised/include/otbMachineLearningModel.txx

...Supervised/include/otbNeuralNetworkMachineLearningModel.h