Add custom overlays

Overlays a custom overlay onto the map. This is done in the WeatherGraphix style, with custom geography residing in the file DIGATMOS.PLR. Edit this file manually (using an ASCII text editor such as Windows Notepad) to make changes. Note that longitude in the west hemisphere is negative, so files imported from WeatherGraphix will need to have the longitude signs inverted. The color of the line is controlled by the "roads and custom lines" setting in File > Preferences > Map.