Ties quantum, melange, and nova network model
Ties quantum, melange, and nova network model

get_instance_nw_info() now returns network model, and keeps the network
info cache up to date.
virt shim and translation in place for virts to get at the old stuff

Change-Id: I070ea7d8564af6c644059d1c209542d250d19ddb

citrix-openstack-build/oslo.versionedobjects,openstack/oslo.versionedobjects