The job queue will allow us to have better flood control and rate
limiting instead of trying to do all the database writes as soon as
parsoid contacts MediaWiki.
On the downside, this means it may take longer for changes to be
reflected in the database and to users, but we already have no promise
for that, so it seems okay.
Note that if you don't have a job queue runner set up, you'll need to
run the runJobs.php script every time to have the jobs execute.
Change-Id: I25fd54734aca4dab09711e7f6aee027654931300