GitLab

- still needs more testing to determine the best combination of versions

- strip both prefix and suffix for VTK and ParaView builds

- resolve problem with working directory:

    Community/catalyst#4
    https://gitlab.kitware.com/paraview/paraview/merge_requests/2436

- only addresses -mesa-prefix behaviour.
  The -mesa-lib option makes no assumptions at all.

STYLE: update versions in makeParaView.example, makeVTK.example

- simple means of distinguishing between types of builds
  (mesa, mpi, python).

- initial attempt for building CGAL as headers-only, and without
  gmp/mpfr

- an example of compiling for pvserver

- make upper-limit on MPI processes command-line configurable for
  makeParaView and add MPI support into makeVTK