(#396) Several fixes regarding Project with plots.

Plots loads the curve data on project open
Plots are removed on project close
Still missing some updates (curve names ...)

ApplicationCode/ProjectDataModel/RimWellLogPlot.h

@@ -43,6 +43,8 @@ public:
     void    addTrace(RimWellLogPlotTrace* trace);
     size_t  traceCount() { return traces.size();}
 
+    void loadDataAndUpdate();
+
     RiuWellLogPlot* viewer();
 
     void zoomDepth(double zoomFactor);