The << operator has been overloaded for a few types (Arrays, Grids, Coords,...

The << operator has been overloaded for a few types (Arrays, Grids, Coords, Dates, Meteo and Station data) and the to_String() methods removed (except for Dates because it might make sense there to get a string) as a way to provide easy debugging output. This makes the meteo_reading example even simpler!