Work on visualizing map objects.

Just hacking interesting pieces together, basically. Added
asynchronous map api load and removed the incongruous load from
index.html.erb. Created arrow-tipped polyline and bound it to a click
listener on the map. The method associated with the listener plops
down circles at the cicks and extends the line through it to show
various hops around the globe. Anyway it's kind of cute, but that's it
right now.
Random comment commit.