[vtkusers] vtkChartXY

[Hagen Mölle]

Hi Marcus and Eric,

Another problem that I will fix:

When removing a plot by index the following code will be executed 
additionally (vtkChartXY.cxx:864).

// Ensure that the bounds are recalculated
this->PlotTransformValid = false;
// Mark the scene as dirty
this->Scene->SetDirty(true);

When removing a plot by using a vtkPlot pointer this code is missing 
(vtkChart.cxx:75). Therefore I will overwrite 
RemovePlotInstance(vtkPlot* plot) in vtkChartXY to accomplish this.

Hagen