Add Prefinery iframe

This is in the same vein as the-domains/thegrid.io#2. Again, I improvised.

Small screens:
![screen shot 2014-06-16 at 15 11 10](https://cloud.githubusercontent.com/assets/84700/3292047/ece82068-f58a-11e3-9761-47c98cec37fe.png)

Large screens:
![screen shot 2014-06-16 at 15 11 26](https://cloud.githubusercontent.com/assets/84700/3292051/f0e814a2-f58a-11e3-87aa-39f595d6ffd9.png)

Error state:
![screen shot 2014-06-16 at 15 15 34](https://cloud.githubusercontent.com/assets/84700/3292054/f416d91a-f58a-11e3-8074-9b0de19c17fb.png)

Success state:
![screen shot 2014-06-16 at 15 15 46](https://cloud.githubusercontent.com/assets/84700/3292055/f6b4d000-f58a-11e3-832d-c9a9eeb756d5.png)