Store longest duration port/protocol/service

[ethack]

Here is where we keep track of the longest connection made for the show-long-connections output.

We could easily store the tuple of port/protocol/service as well. This way we could print out exactly which tuple was associated with the longest connection. As opposed to currently we print out the entire list of tuples and imply that one of the tuples listed is the long connection. A 24 hour TCP long connection is quite a bit different from a 24 hour UDP or ICMP long connection so it would be useful to have this information.