Add start over button to breadcrumb.

Closes #929 

### Normal
![start-over-large](https://cloud.githubusercontent.com/assets/96776/4341185/38bc1c1a-4036-11e4-81b0-a9cf326bf79a.png)

### Small
![start-over-small](https://cloud.githubusercontent.com/assets/96776/4341184/38a01c0e-4036-11e4-985b-8a4f7c12df22.png)