(#396) Added fields for min and max depths to the well log plot

Changing those fields will cause all well trace plots to be updated
accordingly.

ApplicationCode/UserInterface/RiuWellLogPlot.h

@@ -41,6 +41,8 @@ public:
 
     RiuWellLogTracePlot* createTracePlot();
 
+    void setDepthRange(double minDepth, double maxDepth);
+
 private:
     void setDefults();