ENH: Fixed zoom bug when panning histogram-view.

Code/Common/Gui/mvdHistogramWidget.cxx

@@ -173,14 +173,19 @@ HistogramWidget
   m_PlotZoomer->setRubberBandPen( QPen( QColor( 0xFF, 0x44, 0xFF ) ) );
   m_PlotZoomer->setTrackerPen( QPen( QColor( 0xFF, 0x44, 0xFF ) ) );
   */
+#if 1
   m_PlotMagnifier = new QwtPlotMagnifier( m_UI->histogramPlot->canvas() );
   m_PlotMagnifier->setAxisEnabled( QwtPlot::yLeft, false );
   m_PlotMagnifier->setWheelFactor( 1.0 / m_PlotMagnifier->wheelFactor() );
+  m_PlotMagnifier->setMouseButton( Qt::MiddleButton );
+#endif
 
+#if 1
   m_PlotPanner = new QwtPlotPanner( m_UI->histogramPlot->canvas() );
   // m_PlotPanner->setAxisEnabled( QwtPlot::yLeft, false );
   m_PlotPanner->setMouseButton( Qt::RightButton );
   m_PlotPanner->setOrientations( Qt::Horizontal );
+#endif
 
   //
   // CURVES.