Pixel pushing to tighten up design

- Use hairline space to bring 'A to Z' closer together
- Use slightly different column widths on portrait iPad sized screens so
  you can see more content
- Slow the animation a fraction so it is slightly smoother
- Move the sort order up a tiny amount (4px)
Merge pull request #40 from alphagov/design-tweeks

Pixel pushing to tighten up design