Adding magic match URLs

These point to the correct page depending on the state of the match
and the available articles. The correct match is:

* report if it exists
* mbm if it exists
* preview if it exists and the match has not yet started
* otherwise the legacy stats page

This is achieved via a new smart url for matches that checks this info
and performs a redirect accordingly.
Merge branch 'master' of github.com:guardian/frontend into magic-match-links
Remove match link from match tables
Optimisations in MatchController
Merge pull request #3717 from guardian/magic-match-links

Magic match links