[aprssig] (no subject) -- should be Packet Recording

[John Langner WB2OSZ]

The "gen_packets" utility, included with the direwolf TNC package, is a
flexible APRS packet generator.  The resulting audio is placed into a .WAV
file rather than being sent out through the "soundcard."

Options include:
- data bits per second: 300 (HF AFSK), 1200 (default AFSK), 2400 (V.26 style
QPSK), 4800 (V.27 style 8PSK), 9600/19200/38400 (K9NG/G3RUH), or other
arbitrary speed.
- default standard or custom mark/space tones for AFSK.
- number of audio samples per second.
- gradually increasing random noise to test demodulator performance with
poor S/N ratio.