Add support for short aliases for interfaces that are not directly

connected. We now set them up for all nodes that we have a route to.
But, if we have routes to more than one interface, we pick one
essentially at random - if the user cares about the route a packet
takes, they should be using IPs or the 'real' hostnames.  Handles both
host and network routes.

Also, cleaned out some old code that wasn't needed any more.