[aprssig] New experimental GMSK version of APRS Messenger

[Bill V WA7NWP]

> There already is a 40m frequency in use for APRS over PSK/GMSK. In Australia
> VK2IO-63 is Igating on 7034.7 kHz.
>
> It might be worth using this frequency worldwide?

But that doesn't let us use the stock 7070 xtal in the Small Wonder Kits.

Keeping the default 7070 in mind, it'll be interesting to check out
7034.7 here in the Pacific Northwest.

73
Bill - WA7NWP