Add redirections of century URLs (waiting for actual URLs to use)
Merge branch 'master' into century-redirects
Add first known usable century index page url, and a new test.
Redirect century decade stories, and add tests for same.
Make century redirect tests consistent
Merge branch 'master' into century-redirects
Use full live century index url.
merging master into century-redirects
Merge pull request #5309 from guardian/century-redirects

Add century content redirects