Massive renaming in MaterialEditor's family

GUI/coregui/Models/GUIObjectBuilder.cpp

GUI/coregui/Models/SessionModel.cpp

GUI/coregui/Views/MaterialEditor/MaterialEditor.cpp

GUI/coregui/Views/MaterialEditor/MaterialEditor.h

GUI/coregui/Views/MaterialEditor/MaterialEditorDialog.cpp

GUI/coregui/Views/MaterialEditor/MaterialEditorDialog.h

GUI/coregui/Views/MaterialEditor/MaterialEditorWidget.cpp

GUI/coregui/Views/MaterialEditor/MaterialProperty.cpp

GUI/coregui/Views/MaterialEditor/MaterialSvc.cpp

GUI/coregui/Views/MaterialEditor/MaterialSvc.h

GUI/coregui/Views/MaterialEditor/MaterialUtils.cpp

GUI/coregui/Views/PropertyEditor/PropertyBrowserUtils.cpp

GUI/coregui/Views/SampleDesigner/SampleToolBar.cpp

GUI/coregui/Views/TestView.cpp

GUI/coregui/mainwindow/mainwindow.cpp

GUI/coregui/mainwindow/mainwindow.h

GUI/coregui/utils/GUIFunctionalTest.cpp

Tests/UnitTests/TestGUI/TestParticleItems.h

Tests/UnitTests/TestGUI/TestSessionModel.h