Use new sqlite export and scraper metadata URLs

As part of the ScraperWiki Classic archival process, the `/export_sqlite/scraper_name/` and `api.scraperwiki.com/…/getinfo` endpoints are going away, to be replaced by `/export_sqlite/scraper_name.sqlite` and `/scrapers/scraper_name/info`.

This pull request ensures that forking a Classic scraper into Morph.io continues to work before and after this change.

It should be safe to deploy immediately, and *must* be deployed before [2014-03-21T09:00:00Z](http://www.timeanddate.com/worldclock/fixedtime.html?iso=20140321T09) (the last time at which we can guarantee the old endpoints will continue to work).