[aprssig] Message reject behavior

[scott at opentrac.org]

> As far as commands to a tnc, I am not familiar with this...

Well, as far as I know nothing besides the Tracker2 does commands over APRS
messages.  The whole point being that you can control the device remotely
via Igates, unlike a KPC-3 where you need a connected mode link.

Right now the only command that's actually be implemented is RESET, which is
still not quite ready because it resets before it gets a chance to send an
ACK... so the client just keeps sending more RESET commands!

Commands that affect running parameters, like TX interval (or TX inhibit),
and I/Os like the high current switch output, will be next.  Anything that
needs to modify parameters stored in flash is going to be a little more
tricky.

Scott
N1VG