100_contrib_vtk

this one addresses needs for both:
* https://github.com/hpcugent/easybuild-easyconfigs/issues/100
* https://github.com/hpcugent/easybuild-easyblocks/issues/82

It builds OK but, we still need someone to adopt it in practice, just to be sure; 
I recommend to follow-up within #100, it should be minimal work.