Support non-default TRP and TID ports

Support non-default TRP and TID ports

  * Include trust_router and next_hop ports in inforecs, routes, and
    update msgs
    - affects encoders and decoders
    - use next_hop from the inforec instead of assuming it is the
      peer's server address
    - default next_hop to the trust_router for backward compatibility
    - default both ports to the standard well-known ports if not given
  * fill in local routes with our hostname/port
    - no longer permit empty next_hop fields
  * Update filter handlers
    - handle next_hop field
    - use hostname:port format (or just hostname with default port)
    - handle next_hop field
  * Keep track of AAA server ports
  * Be more careful with tr_msg JSON helper return values
  * Use tr_name_strdup() to avoid ad hoc conversion from name to string
  * Use signed int as port to allow -1 as an invalid port indicator
  * Remove now-obsolete tr_aaa_server_from_name() function