systat - Improve pftop output

systat - Improve pftop output

* Fix bugs where ICMP states were display bandwidth as '<huge>' .

* Fix bugs where the RB tree compare code would sometimes collapse
  distinct states, creating confusion.

* Greatly improve readability by reformatting addresses and ports,
  in particular truncating IPV6 addresses to fit better.

* Reduce jumping around of display elements as bandwidth values change.
  Instead of sorting by the current bandwidth the display is sorted
  by the 1/8 decay bandwidth.