FreeSurfer's tool mris_convert (surface format coversion)

[MontrealSergiy]

We got a request to integrate FreeSurfer command-line tool mris_convert to support email?

Should we add it ?

[MontrealSergiy]

I think for now we can add the minimal set of option, if user asks for more we will add latter.

[MontrealSergiy]

here is the first draft (untested)