Use geodesic plugin for leaflet do correctly display great circle
paths between waypoints and handle wrapping across -180deg of latitude.
The entire leaflet library seems to have an issue wrapping around
-180/+180 deg of latitude :-/
new manual weather configuration based on a
http://en.wikipedia.org/wiki/St%C3%BCve_diagram Stuve (Stüve) Diagram.
work in progress, up to now it's just displaying current weather, edits
are not yet written to fg.