rm Qt's tr operator from GUI.

GUI/coregui/Models/SessionModel.cpp

GUI/coregui/Views/InfoWidgets/InfoWidget.cpp

GUI/coregui/Views/InfoWidgets/WarningSignWidget.cpp

GUI/coregui/Views/InstrumentView.cpp

...oregui/Views/InstrumentWidgets/InstrumentEditorWidget.cpp

.../IntensityDataWidgets/ObsoleteIntensityDataPlotWidget.cpp

GUI/coregui/Views/JobWidgets/JobListWidget.cpp

GUI/coregui/Views/JobWidgets/SliderSettingsWidget.cpp

GUI/coregui/Views/MaterialEditor/MaterialEditorDialog.cpp

GUI/coregui/Views/SampleDesigner/DesignerMimeData.cpp

GUI/coregui/Views/SampleDesigner/ILayerView.cpp

GUI/coregui/Views/SampleDesigner/SampleToolBar.cpp

GUI/coregui/Views/SampleView.cpp

GUI/coregui/Views/SimulationWidgets/PythonScriptWidget.cpp

.../Views/SimulationWidgets/SimulationDataSelectorWidget.cpp

...coregui/Views/SimulationWidgets/SimulationSetupWidget.cpp

GUI/coregui/Views/WelcomeView.cpp

GUI/coregui/Views/widgetbox/widgetbox.cpp

GUI/coregui/Views/widgetbox/widgetboxtreewidget.cpp

GUI/coregui/mainwindow/aboutapplicationdialog.cpp