* cloudstack: cs_portforward: implement vpc support
* cloudstack: cs_portforward: add vpc and network to returns
* cloudstack: cs_portforward: networkid must not be used for rule listing
* cloudstack: fail for get_network when vpc but no network name
This seem to be a global pattern for get_network, we want to enforce a
network name to be set if a vpn param is given.
This is used for cs_portforward.
* cloudstack: cs_portforward: doc: fix defaults for vpc, network