Control over VerticalConfigurationPanel

[GoogleCodeExporter]

It would be useful to have the possibility to remove elements from the 
VerticalConfigurationPanel in the JSurfacePanel class.

Or alternatively to automatically remove the ButtonGroup with the curves 
selection (first, second, both) when there is only one curve in the plot and 
the second is null.

Original issue reported on code.google.com by [email protected] on 27 Mar 2012 at 11:35