Commercial books high

Creation of books high relevancy component.

Uses the new full width banding. Only on article pages for desktop and above, (although layout is working across all breakpoints.

No before as it didn't exist.

![screen shot 2014-05-13 at 10 55 43](https://cloud.githubusercontent.com/assets/1303616/2955755/d566d52c-da84-11e3-89f4-923938d7be99.png)

Mobile for reference;
![screen shot 2014-05-13 at 10 56 42](https://cloud.githubusercontent.com/assets/1303616/2955766/f595bd0e-da84-11e3-97f2-2b9211d32999.png)