It is valid for an interface to reference another, otherwise undeclared,
interface (i.e. a bond enslaves eth0 without eth0 having its own iface stanza).
In order to associate the two interfaces, the undeclared interface needs to be
implicitly created so that it can be referenced by the other. This adds the
capability to forward-declare interfaces in addition to cleaning up the
process a little bit.
Adding the flag -convertNetconf which is used to specify the config
format to convert from (right now, only 'debian' is supported).
Once the network configs are generated, they are written to
systemd's runtime network directory and the network is restarted.
