New cards

- New card design
- Flexible by default
- Far more simple than existing cards
- New styles are hidden behind a feature flag

![screen shot 2014-08-13 at 15 15 29](https://cloud.githubusercontent.com/assets/271645/3906592/7ba864de-22f4-11e4-8bd1-985d1426a32d.png)
![screen shot 2014-08-13 at 15 15 45](https://cloud.githubusercontent.com/assets/271645/3906590/7ba60f18-22f4-11e4-81b8-075420a861d1.png)
![screen shot 2014-08-13 at 15 15 57](https://cloud.githubusercontent.com/assets/271645/3906591/7ba81ad8-22f4-11e4-908b-127403571467.png)
![screen shot 2014-08-13 at 15 16 09](https://cloud.githubusercontent.com/assets/271645/3906593/7ba91154-22f4-11e4-87bc-83a3b0dd4d41.png)
![screen shot 2014-08-13 at 15 16 20](https://cloud.githubusercontent.com/assets/271645/3906594/7baa4ea2-22f4-11e4-9e51-a829c0454bf0.png)
![screen shot 2014-08-13 at 15 16 28](https://cloud.githubusercontent.com/assets/271645/3906595/7bb8fab0-22f4-11e4-8799-5a9bcafec2c0.png)


To see the cards checkout this branch and flip the `cards_version` setting in the application config to `v2`.
Could this be handled in the view instead? 

```
.card__desc{class: img.present? ? 'accessibility' : false
```