This static library is a copied version of the code in GNOME 3.0's control center panel 'datetime', which itself is a version of Ubiquity's map ported to C.

Ideally in the future, we can have all three packages using the same code.  But for now, for time reasons (hah), it's just a copy.

To update this copy, put newer versions of the code and data files in place; then fix up any GTK3-isms and add cc_timezone_map_set_coords and friends.  And the watermark.