[Paraview] PV 3.10.0 filters & contributing code

[Utkarsh Ayachit]

> Regarding the contributing code, I applause! The work-flow you
> proposed is the simplest one. Do you think it would possible
> to use the submodule mechanism from git, so that the contributed
> plugins are directly built in the ParaView tree without interfering
> with the developers' branches ?

Yes, they could, but I suppose it will be better to host that
submodule repo at Kitware. Of course, ParaView will start including
contributed plugins only after review and such. In any case, plugins
should setup so that they can build externally without too much of an
issue.

Utkarsh