[Xastir] New user to xastir program

[Bill Vodall]

> I used used U7??? Modem with networked agwpe and wine. Basically a experiment which I chatted on 30m aprs 800 miles. The modem worked but no waterfall on the U7??? Modem.

Direwolf is open source and runs on all platforms.  UZ7HO has a
waterfall but is windows only.

  * https://github.com/wb2osz/direwolf
  * http://uz7.ho.ua/packetradio.htm

Functional use with Xastir should be the same.

Bill, WA7NWP