While creating a port, neutron gets the VN to check permissions. This can get very expensive if we walk the backrefs. Scince the instance count is not really needed as part of get VN, we are going to return 0 instead of paying the penatly of getting all the instances
Removing another un-necessary instace of back_ref access from VN
Merge pull request #4 from Juniper/anishm_vmcount3

While creating a port, neutron gets the VN to check permissions. This ca...