Merge branch 'sampling_composite' into develop

...Applications/AppClassification/app/otbSampleSelection.cxx

...ations/AppClassification/app/otbTrainImagesClassifier.cxx

...ations/AppClassification/app/otbTrainVectorClassifier.cxx

Modules/Applications/AppClassification/test/CMakeLists.txt

Modules/Filtering/Statistics/include/otbPeriodicSampler.h

Modules/Filtering/Statistics/src/otbPeriodicSampler.cxx

Modules/Filtering/Statistics/test/otbSamplerTest.cxx

...rning/Sampling/include/otbOGRDataToSamplePositionFilter.h

...ing/Sampling/include/otbOGRDataToSamplePositionFilter.txx

...pplicationEngine/include/otbWrapperCompositeApplication.h

.../ApplicationEngine/src/otbWrapperCompositeApplication.cxx