ParaView Catalyst In Situ engine plugin

[caitlinross]

Adding the in situ vis engine plugin. The only dependency is the Catalyst stub library, not ParaView.

[vicentebolea]

This looks great, I will have it reviewed ASAP

[caitlinross]

@vicentebolea looks like the images with catalyst are good!

[caitlinross]

@vicentebolea made the requested changes, and a few other minor things (e.g., forgot that I still had the paraview license info on the plugin files, instead of changing to adios).

[vicentebolea]

Last one, please squash the commits into buildable units

[caitlinross]

@vicentebolea made the changes