cleaning up commented code

GUI/coregui/Models/BeamDistributionItem.cpp

GUI/coregui/Models/BeamDistributionItem.h

GUI/coregui/Models/DistributionItem.cpp

GUI/coregui/Models/DistributionItem.h

GUI/coregui/Models/GroupProperty.cpp

GUI/coregui/Models/IntensityDataItem.cpp

GUI/coregui/Models/ItemFactory.cpp

GUI/coregui/Models/JobItem.cpp

GUI/coregui/Models/JobModel.cpp

GUI/coregui/Models/MaterialItem.cpp

GUI/coregui/Models/ModelMapper.cpp

GUI/coregui/Models/ModelMapper.h

GUI/coregui/Models/MultiLayerItem.cpp

GUI/coregui/Models/ParameterModelBuilder.cpp

GUI/coregui/Models/ParticleCoreShellItem.cpp

GUI/coregui/Models/ParticleCoreShellItem.h

GUI/coregui/Models/ParticleItem.cpp

GUI/coregui/Models/PropertyItem.cpp

GUI/coregui/Models/PropertyItem.h

GUI/coregui/Models/SampleModel.cpp