Adds standalone page for speakers' list

The page looks like this
![Screen Shot 2013-04-12 at 11 15 08 PM](https://f.cloud.github.com/assets/1211471/374951/be78c3de-a3ad-11e2-954b-d0f870983573.png)

It's all dynamically generated.

New speakers can be added at data/speakers.yml