rename ns; forward decl

GUI/Model/Job/JobModelFunctions.cpp

GUI/Model/Material/MaterialItemUtils.cpp

GUI/Model/Material/MaterialItemUtils.h

GUI/Model/Material/MaterialModel.cpp

GUI/Model/Sample/GUIDomainSampleVisitor.cpp

GUI/Model/Sample/ItemWithMaterial.cpp

GUI/Model/Sample/LayerItem.cpp

GUI/Model/Session/SessionModel.cpp

GUI/View/MaterialEditor/MaterialEditorDialog.cpp

GUI/View/PropertyEditor/CustomEditors.cpp

GUI/View/PropertyEditor/PropertyEditorFactory.cpp

GUI/View/SampleDesigner/MaterialInplaceForm.cpp

GUI/Widget/Common/DesignerHelper.cpp

Tests/Unit/GUI/TestMaterialModel.cpp