Implement the new design for the Code Week website

This is an iteration of the Code Week website to include a new design, the new logo, and a clearer introduction to what Code Week is.

![ecw-open-sans](https://cloud.githubusercontent.com/assets/71922/2741250/348a46ec-c6e4-11e3-998f-49487dd7dfa8.png)
![code-week-iphone](https://cloud.githubusercontent.com/assets/71922/2741251/38720f4c-c6e4-11e3-9abf-66e090b91900.png)