Make the responsive layout widerer!

As part of the ongoing efforts to make our site a flexy, bendy, squashable thing the layout needs to become wider. To do this I have:

- Increased the max width of the `.row__inner` class to `1160`
- Added a new stack layout with rather 'magic' card container (http://codepen.io/anon/pen/BHjfF)
- Upgraded to Sass 3.3.x

![screen shot 2014-07-28 at 14 04 57](https://cloud.githubusercontent.com/assets/271645/3733907/e6c5ebb2-170d-11e4-8f68-d1575bf0cb19.png)
![screen shot 2014-07-28 at 14 05 50](https://cloud.githubusercontent.com/assets/271645/3733908/e6c6b3ee-170d-11e4-9993-9c76a980f4b2.png)
![screen shot 2014-07-28 at 14 15 54](https://cloud.githubusercontent.com/assets/271645/3733909/e6c72888-170d-11e4-9052-6c6c10406860.png)