(#466) Made sure that selecting plots and plot tracks both work

Both widgets accept focus events and select the corresponding items in
the project tree view. Focus is cleared immediately in the focus event
handlers, so that plot tracks won't steal focus from the plots in
subsequent selections of plots.

ApplicationCode/UserInterface/RiuWellLogPlot.h

@@ -28,6 +28,7 @@ class RiuWellLogTracePlot;
 
 class QHBoxLayout;
 class QScrollBar;
+class QFocusEvent;
 
 //==================================================================================================
 //
@@ -48,6 +49,9 @@ public:
 
     void setDepthRangeAndReplot(double minDepth, double maxDepth);
 
+protected:
+    virtual void focusInEvent(QFocusEvent* event);
+
 private:
     void updateScrollBar(double minDepth, double maxDepth);