* introduce a section on SYNTAX to document the handling   spaces and comma-separated lists of arguments;
* introduce a section on SYNTAX to document the handling
  spaces and comma-separated lists of arguments;

* reword the description of address specifications, to include
  previous and current changes for address sets and lists;

* document the new '-n' flag.

* update the section on differences between ipfw1 and ipfw2
  (this is becoming boring!)

MFC after: 3 days

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase