sanity checking on the interfaces and wires tables, creates interfaces
for the switch side of all wires, as well as any other missing
interfaces for wires. Eventually the primary key for the wires table
will be node_id1,iface1,node_id2,iface2, but we are ways off from that.

Not that wires between switches that do not have an existing for at
least one side, are not handled yet since there is not enough
information to generate the two missing interfaces. Have to think about
that, but not a problem for now.