Multi-threading improvement for offscreen

src/.gitignore

src/Makefile.am

src/Makefile.in

src/datacontainer/PropertyPlotDataContainer.cpp

src/main.cpp

src/mainoffscreenplot.cpp

src/maintest.cpp

src/maintest2.cpp

src/manager/OffScreenPlotManager.cpp

src/manager/OffScreenPlotManager.h

src/manager/PlotManager.cpp

src/manager/RequestDealerManager.cpp

src/manager/mpl/MplEventManager.cpp

src/manager/mpl/MplEventManager.h

src/plot/EmptyPlot.cpp

src/plot/Plot1D.cpp

src/plot/Plot1D.h

src/plot/Plot2D.cpp

src/plot/PlotWindow.cpp

src/plot/PlotWindow.h