Make the header blue

- edition switch moved to the right, and subscribe out of ‘more’
- new, single style of pop up menus
- new and larger icons
- new colours
- services links moved into mega nav
- smoother meganav open/close animation 

![screen shot 2014-08-05 at 11 03 47](https://cloud.githubusercontent.com/assets/867233/3809780/1077a75a-1c88-11e4-8938-6aec1f5688ad.png)

:point_down: 

![screen shot 2014-08-05 at 11 02 55](https://cloud.githubusercontent.com/assets/867233/3809782/135f2344-1c88-11e4-9825-7c208ef4ad20.png)


I think it was nicer adding the `ul` in the `JS` as it has no meaning without it's items, which you will not get unless you have `JS` on.

I haven't looked thoroughly through the code, but are we using `role="navigation"` as lists can be a pain for screenreaders (perhaps not for the PR)?