[wxqc] Undergrond weather for Davis Inst. Versionv5.5.1

[Al Huggard]

Those of us using Davis version 5.5.1 and belonging to the weather
underground must down load an add-on from the /weather underground at the
following site.

http://www.wunderground.com/weatherstation/index.asp

Davis made a company decision not to include the weather underground in the
supplied formats.

This is FYI for all Davis software users.