New cards

- New card design
- Flexible by default
- A single card component (and ads, but meh)
- New styles are hidden behind a feature flag
- Makes dreams come true*

![screen shot 2014-09-09 at 12 26 16](https://cloud.githubusercontent.com/assets/271645/4200663/67b4a4d0-3814-11e4-9766-eb008e63afe8.png)
![screen shot 2014-09-09 at 12 26 40](https://cloud.githubusercontent.com/assets/271645/4200662/67b2185a-3814-11e4-8ea0-f4319e68eda0.png)
![screen shot 2014-09-09 at 12 26 55](https://cloud.githubusercontent.com/assets/271645/4200665/67b70de2-3814-11e4-8da1-5b4a8c955fff.png)
![screen shot 2014-09-09 at 12 27 04](https://cloud.githubusercontent.com/assets/271645/4200668/67c77a42-3814-11e4-9484-078fd009e3d9.png)
![screen shot 2014-09-09 at 12 27 26](https://cloud.githubusercontent.com/assets/271645/4200664/67b55dee-3814-11e4-8830-d613899332a4.png)
![screen shot 2014-09-09 at 12 27 37](https://cloud.githubusercontent.com/assets/271645/4200666/67c1b652-3814-11e4-859d-0e5768325bef.png)
![screen shot 2014-09-09 at 12 27 50](https://cloud.githubusercontent.com/assets/271645/4200667/67c68ef2-3814-11e4-9ec1-b9c9537c539a.png)
![screen shot 2014-09-09 at 12 28 01](https://cloud.githubusercontent.com/assets/271645/4200669/67c984cc-3814-11e4-99b2-560333dabee2.png)

To see the cards checkout this branch and flip the `cards_version` setting in the application config to `v2`.
Can't these stop being cards now? Could we mark this code to be deleted once the ad rail is done?