Switch URL rewriter to only work with absolute paths.
Add some publish-validations for links in govspeak.
Whitespace.
Rework EditionPublisher to expose multiple failure reasons.
Don't permit force publishing or 2nd eyes on editions with bad links
Modernise partial render style.
Styleguide semicolons.
Add a link errors interface to edition editing.
Fix govspeak helper tests.
Remove force-publish restriction on 2nd eyes.

This logic needs to live in an as-yet non-existent
edition submitter.
Basic fix-up of alert styles.

This needs a site-wide cleanup as part of the
admin restyle.
Merge pull request #1032 from alphagov/basic-validation-for-markdown-links

Basic validation for markdown links

https://www.pivotaltracker.com/story/show/48033625
https://www.pivotaltracker.com/story/show/60397200
https://www.pivotaltracker.com/story/show/60397572