Labs retires the old ipv6-measurement graphs

As the code has reached a stable service, we’ve decided to retire the old tree of graphs.

For people with saved URLs, it should redirect to the new service, and should map an ASN or Economy to the right dataset.

For people who are farming the site for json data, .json URLs should persist and continue to work. We are logging whats taken, so we can port that into the new framework as a data service too. When thats done, the .json URL will also redirect.