To do:  FTN:Packet

- Reorganize the functions, so that instead of a read and a write packet
function; there are functions to open and close the packet file being read or
written, reading or writing the packet header are separate functions, and then
reading or writing the messsages to or from a packet file are also separate
functions?
- Also add other functions as neccessary:  one for generating a serial number,
one for generating a name for a standard packet file, one for generating an
ftsc standard date.
- Add reference to ftsc documentation and/or to the ftsc web site.

    write_ftn_packet()
- When doing, for instance, two messages:  two messages are making it into
the packets but they're both the text of the second message.
- Also the serial number for the MSGID is coming up as the same for both.
When code a better way of getting a 8 char serial number to use, add it as a
function to the module?
- The write up and variable usages for the packet format per FTS-0001 could
be rewritten to more closely match the current documentation, esp. the listed
order.
- Change the name of the appropriate fields in the packet related hashes to
being named after how they are named in the FTS-0001 documentation.

    read_ftn_packet()
- Change the name of the appropriate fields in the packet related hashes to
being named after how they are named in the fts-0001 documentation.
- The zone number information is not being pulled what is available in the
packet;  needed to set the from_node & to_node variables instead of assuming
zone 1.  It is in the packet header (being skipped in the current code) instead
of in the message header.  Or could use the zone number from the message id if
available.
  