Waypoint and compile fix

These two commits fix two things:

1: A bug where if you added a bunch of "offline" waypoints, THEN opened the waypoint list, the waypoint list woudl be empty until you added another waypoint.
2: Compile errors on windows. MSVC compiler does not let you initialize static const floats in a class definition, (Only integral values). #warning is also not a valid preprocessor directive on windows, so added a #pragma message() inside an #ifdef Q_OS_WIN.