Remove margin on top of header
Fix alignment for sections
Update arrows

- Remove link-out arrows
- In order to get the arrows flush against the right of the subsection-title AND sprited I've had to add a span (called 'js-toggle') with the background of the arrow. Because the headings are of variable height and variable width and it's not possible to specify px-from-the-right (only the rightness as a % of the whole width) I it wasn't possible to get a sprite where for very long titles the other arrow image will sneak into view.
- The toggle div is added by JS on the collapsible class since we don't need it if the section isn't collapsible.
fix alignment of open/close all links
Rename 'Main contents' to 'Contents' in breadcrumb
Correct titles

- Make h2/h3s bold.
- Add body with override to a .govspeak class
Updating metadata headings
Add retina sizes
Merge pull request #32 from alphagov/update-design-for-generalisation

Update design for generalisation