Fix #296: the network lookup by name now returns [] if the name is not found, or if the name was not a network
Fix #296: the network lookup by name now returns [] if the name is not found, or if the name was not a network

amdouglas/OpenPNM,PMEAL/OpenPNM,amdouglas/OpenPNM,TomTranter/OpenPNM,stadelmanma/OpenPNM