Apply standard GOV.UK breadcrumb styling

Makes sense for the manuals breadcrumbs to be consistent with the existing GOV.UK style elsewhere.
Compare the breadcrumbs here: https://www.gov.uk/types-of-school vs. here: https://www.gov.uk/guidance/content-design/what-is-content-design to see the current difference.

This PR changes the manual breadcrumb style to this: 

![man_bc](https://cloud.githubusercontent.com/assets/265403/4666272/f2af3c30-5551-11e4-91a7-96ddb3973859.png)