Adds source port matching support when IP matching is used:

  [example]
  type = identify
  match = 1.2.3.4:5060/32, 1.2.3.4:6000/32, asterisk.org:4444

If the IP matches but the source port does not, we reject and search for
alternatives. SRV lookups are still performed if enabled (srv_lookups = yes),
unless the configured FQDN includes a port number in which case just a host
lookup is performed.

ASTERISK-28639 #close
Reported by: Mitch Claborn

Change-Id: I256d5bd5d478b95f526e2f80ace31b690eebba92