Add ability to set up interface for temporary IP

with ``--set-interface``, we can assign and use any IP address (except 127.0.0.1) in the VM during the initialization. It would be convenient, to build VMs in any environment then deploy them to production env without any changes.
Do you think we can get a good short flag for it as well? I know -i is not available, do you think we have any good options?