Tighten the scope for the Bootstrap span4 bodge rule
Add an external link icon to the slug

This makes it clearer that the slug is a link to the content on the
live site.
Make the archive view a separate page

This is in preparation for changing the button group to tabs.
Use tabs instead of the button groups

Following Maslow's change to use tabs instead of button groups, I'm
going to abandon the change to remove tabs here.
Fix a unit test for the ArtefactsHelper
First pass at a new integration test for the edit form

This asserts that many elements of the form are displayed correctly.
Conflicts:

	test/integration/artefacts_edit_test.rb
Fix functional tests for history

This moves two tests for the show action into the correct part of this
functional test file, and changes the history test to request the
history action now instead.
Conflicts:

	test/functional/artefacts_controller_test.rb
Allow the slug to be changed for a draft artefact

The slug can be changed for an artefact whilst it is in the draft state,
so display the slug field for draft artefacts.
Don't hardcode urls