Added a from_vtk method to the Import class that calls io.VTK.load.  This IO method needs some work to match the behavior of CSV, but the rough outline is there.
Added a from_vtk method to the Import class that calls io.VTK.load.  This IO method needs some work to match the behavior of CSV, but the rough outline is there.

TomTranter/OpenPNM,stadelmanma/OpenPNM,PMEAL/OpenPNM