[Paraview] PV Web scrollwheel for zoom, wrong legend

[Daniel Zuidinga]

I added the lines but scroll wheel does not work
>
> Look at ${pv_src}/Web/Python/paraview/web/protocols.py 
>  #ParaViewWebMouseHandler
> vs ${pv_src}/VTK/Web/Python/vtk/web/protocols.py   #vtkWebMouseHandler
>
> it seems the paraview one is missing:
>
>       if event.has_key("scroll"):
>             pvevent.SetScroll(event["scroll"])
>
> Just add it to your paraview python file.
>