[vtkusers] events freeze X using vtk with wxPython

[John Hunter]

I have been doing some more testing with the wxVTKRenderingWindow
demo.  Earlier, I was not able to figure out precisely what event was
causing the freezing because it was such a hassle to recover from the
freeze that I couldn't do many tests.

But now I am doing 
> at now + 2 minute
at> killall python

so even if X freezes, I recover the system in 2 minutes and can test
again.

It appears the event that infallibly causes the freeze is a left mouse
click on the cone.  The resize event does not tend to cause a freeze,
as I initially thought.  But so far the click event appears to do it
every time.  Perhaps you also want to try this case?

Thanks again,
John Hunter