Add SUL rosette favicon.

#### Before
![favicon-before](https://cloud.githubusercontent.com/assets/96776/3632974/4f9fa680-0ed2-11e4-8ee0-f4e8034f5d17.png)

#### After
![favicon-after](https://cloud.githubusercontent.com/assets/96776/3632975/4fa17352-0ed2-11e4-9760-517118034212.png)