EO top bar branding

Two things:

**Update dpm top bar to use agreed branding**
- New image and spacing to make it work
- Use logo formatted name without adding line breaks on eo pages

https://www.pivotaltracker.com/story/show/48560501

and:

**Custom top bar colours for EO pages**
Enable the possibility of having a custom top bar colour. Currently this
is only going to be turned on for the EO offices while we think about
which colours to use for other departments.

https://www.pivotaltracker.com/story/show/48560651