[i311] GUI: fix for a simulation with specular data (Closes #311)

GUI/Model/BaseItem/SessionItem.h

GUI/Model/Data/DataItem.cpp

GUI/Model/Data/DataItem.h

GUI/Model/Data/IntensityDataItem.cpp

GUI/Model/Data/IntensityDataItem.h

GUI/Model/Device/AxesItems.cpp

GUI/Model/Device/AxesItems.h

GUI/Model/Model/JobFunctions.cpp

GUI/Model/Model/JobModel.cpp

GUI/Model/Model/JobModel.h

GUI/View/Job/JobListModel.cpp

GUI/View/Job/JobListModel.h

GUI/View/PlotComparison/FitComparisonController.cpp

GUI/View/PlotComparison/FitComparisonViewController.cpp

GUI/View/PlotComparison/Plot1D.cpp

GUI/View/PlotUtil/ColorMap.cpp

GUI/View/PlotUtil/IntensityDataPropertyWidget.cpp

GUI/View/Projection/ProjectionsEditor.cpp

GUI/View/Projection/ProjectionsPlot.cpp

GUI/View/Toplevel/SimulationView.cpp