Add South American Countries.

I tested this locally, and it works pretty well – with a couple caveats.

- The label that shows when hovering over Chile and Argentina is obscured (see screenshots below)
- The southern tip of the continent is obscured by the timer.

![screen shot 2013-11-28 at 10 18 44 am](https://f.cloud.github.com/assets/173440/1641093/eb604790-5849-11e3-9248-d45dddc23665.png)
![screen shot 2013-11-28 at 10 18 38 am](https://f.cloud.github.com/assets/173440/1641094/ec293718-5849-11e3-97dc-e30ad194fe1e.png)

I'm not sure that I should attempt to fix these myself, but I can take a crack at it if you'd like.

I also had to do a little bit of dataset massaging to make this work the way I wanted. I kept the Falkland Islands, even though they're part of the UK, and I added French Guiana even though it's part of France. If you think I should change this at all, I'm happy to.