tested with IP and VTP generator. seems to work. Merging now
tested with IP and VTP generator. seems to work. Merging now


Former-commit-id: af737c2bbc4c7f902d20e4f74388f253d7ffddec
Former-commit-id: 9cf1e5ec0651f6ec19e17d0648b7766d2e3caaf3
stadelmanma/OpenPNM,PMEAL/OpenPNM,amdouglas/OpenPNM,amdouglas/OpenPNM,TomTranter/OpenPNM