Extended dataset and certificate view

This displays more information about the dataset in an expandable area - deployed to [staging](http://staging.certificates.theodi.org/datasets)

![image](https://f.cloud.github.com/assets/51385/1073750/efad8e60-14ac-11e3-81aa-6e3fb03ff690.png)

resolves #509, touch #498, UI - #495

### todo

- [x] display the data/content licences properly*
- [x] localisation
- [x] style tweaks - [adjust proportions](https://github.com/theodi/open-data-certificate/pull/558#issuecomment-23774296)
- [x] style tweaks - [reduce font-size](https://github.com/theodi/open-data-certificate/pull/558#issuecomment-23774296)

\*@JeniT, did you want the data & content licences to be combined if they were the same?