Fix bug 786320: Redirect DevNews page and feeds

Believe it or not, we still get a significant number of requests for
these resources -- around 13,000 per year.
fix bug 999102: Respond with 404 for $history where document has no revisions
Merge pull request #2284 from openjck/emulate-devnews

Fix bug 786320: Redirect DevNews page and feeds
Merge pull request #2315 from lmorchard/999102-history-error

fix bug 999102: Respond with 404 for $history where document has no revisions