Fix tabindex on index page

The tabindex needs to be added to the element which contains the
individual list not the element which contains all the lists.
Remove outline focus from columns

When calling focus on the elements it puts a blue glow around the list.
This removes that glow as it is confusing.
Merge pull request #22 from alphagov/remove-outline

Remove outline focus from columns
No-op on page load pop, fix detailed guide pop

Loading detailed guides in is failing due to changes in method arguments
not being updated.

Also don't try and update the page if the page we are currently showing
is the page we are going to show.
Merge pull request #24 from alphagov/safari-fixes

No-op on page load pop, fix detailed guide pop
Merge pull request #20 from alphagov/fix-tab-index

Fix tabindex on index page
Add loading indicator

So that a user knows something is happening display a loading indicator
while the Ajax request is performed.

Add `aria-busy` to let screen readers know something is happening.
Improve narrow tablet screen styles

- Removing the A-Z title for narrow tablet sized screens mean long words
  won't be longer than the column they have to be displayed in.
- Increasing the minimum height for narrow screens means the subsection
  border and background will always overlap the whole of the root list
Add IE specific stylesheets

This lets them get desktop styles rather than mobile stylesheets. Also
add in IE specific varables for JavaScript incase they are needed in the
future.

Add the new stylesheets to the precompile so they are on production.
Merge pull request #27 from alphagov/ie-fixes

Add IE specific stylesheets
Merge pull request #25 from alphagov/tablet-fixes

Improve narrow tablet screen styles
Merge pull request #23 from alphagov/loading-indicator

Add loading indicator
Show section descriptions in section lists

- Update mustache to conditionally show descriptions
- Update section and subsection pages to show descriptions
- Update styles for descriptions
- Update navigate to use `currentTarget` rather than `target`.
  `currentTarget` will contain the element that jQuery is attaching the
  event to rather than the element within the link which was acutally
  clicked.
- Update `getTitle` to get the title out of a list item regardless of if
  it is in a heading in the list item or the list item is the title.