Course instance

Adding the course instance template as per Brian's IA work. Here's how it looks:

![open data institute courses](https://f.cloud.github.com/assets/109774/1401012/892b3210-3cce-11e3-9ed9-6140ff648168.png)

The only thing I haven't added is Other Courses, as I'm not (yet) sure of the best way to do it.