Added a degree-minute-second coordinate formatter for general use. Use this formatter in iosapp and osxapp.
Added unit tests for the coordinate formatter and for round-tripping geometry types through NSValue.
Added an offline pack download manager to osxapp to demonstrate the use of MGLOfflineStorage with Cocoa Bindings. Like the Offline Packs view controller in iosapp, new packs are added based on the foremost map view’s current state. Double-clicking a complete offline pack opens a new map window to the pack’s bounds.
Even with the system preference set to close windows when quitting, the user would still expect this map-centric application to remember the last viewed map, because the world map isn’t quite as interesting.
Instead of forcing the system to restore windows between sessions (which confusingly switches the behavior of ⌘Q and ⌥⌘Q), honor the preference but have each new window inherit the style of the previous main window.
