Provides icon fallback in search when repository type not available

Before:
![screen shot 2014-11-17 at 4 50 47 pm](https://cloud.githubusercontent.com/assets/186715/5192564/6ed6f986-74ad-11e4-8b08-0160df318476.png)

After:
![screen shot 2014-11-25 at 2 16 42 pm](https://cloud.githubusercontent.com/assets/186715/5192605/bfaffb82-74ad-11e4-9d8b-45eff00d4fa9.png)