WP style user-friendly selection of geo-coordinates (decimal degrees).
https://code.jquery.com/jquery-2.1.0.min.js
https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.13/d3.min.js
https://cdnjs.cloudflare.com/ajax/libs/topojson/1.1.0/topojson.min.js
https://cdnjs.cloudflare.com/ajax/libs/d3-geo-projection/0.2.9/d3.geo.projection.min.js
https://maxcdn.bootstrapcdn.com/bootstrap/3.3.1/js/bootstrap.min.js