V0.6.0 – Switched out Leaflet for mapbox.js 1.0

Some parts of this app were a bit **hacky** in their original implementation. Some of this has been addressed in the latest release of mapbox.js, which is now being provided as a plugin for Leaflet. Panning the map and clicking on hexes is now much, much smoother, particularly on mobile. Cut down on some code too.

Obviously this is not pegged to anything urgent, but it would be nice if it could make it's way out in a future deploy.