ENH: reorganize the applications in subdirs

Applications/CMakeLists.txt

Applications/Hyperspectral/CMakeLists.txt

Applications/Hyperspectral/otbHyperspectralUnmixing.cxx

Applications/Test/CMakeLists.txt

Applications/Test/otbAddition.cxx

Applications/Test/otbAllocateOutput.cxx

Applications/Test/otbCopyInput.cxx

Applications/Test/otbInternalReader.cxx

Applications/Test/otbTestApplication.cxx

Applications/Util/CMakeLists.txt

Applications/Util/otbExtractROI.cxx

Applications/Util/otbRescale.cxx

Applications/Util/otbSmoothing.cxx

Applications/VectorImageFactory.cxx