Basic well log plot functionality with dummy data up & running

Traces can be added to and deleted from well log plots, and curves with
dummy data can be added and deleted. TODO: Replace dummy data with real
well log data and data extracted from the model.

ApplicationCode/ProjectDataModel/RimWellLogPlot.h

@@ -25,8 +25,8 @@
 
 #include <QPointer>
 
-class RimWellLogPlotTrace;
 class RiuWellLogPlot;
+class RimWellLogPlotTrace;
 
 
 //==================================================================================================
@@ -45,6 +45,8 @@ public:
 
     void addTrace();
 
+    RiuWellLogPlot* viewer();
+
 protected:
 
     // Overridden PDM methods