Respect metabook lang setting when localizing attributions page.

Change-Id: I090df946c7aac3c35322f8aab1c8169de8b5b05c
Fetch authors in larger batches; fetch authors for specific article revid.

Change-Id: Ic05e5d99ad4072416028b78aab8364ffdf237238
Skip wikitext fetch when `--no-compat` option is given.

The old pipeline used to parse the wikitext of the various image
pages, etc, in order to extract contributors and license information.
We have a dedicated API request for this now, so skip the unnecessary
wikitext fetch.

Change-Id: Ief3e447cd77607735d43ff7934bf8c949bc5e65b