Autocreate accounts on meta, mediawiki.org, loginwiki
On the fly autocreation of accounts when a user visits a wiki the
first time is too late for some things, such as OAuth authorizations.
For the OAuth central wiki (currently mw.o, in the future meta),
use a job to create the account immediately.
Also add loginwiki as normal (browser-based) registration creates
an account there anyway, and the same thing not happening for
API-based registration makes spam fighting harder.
Soft-depends on I3937b9e6d0df1ef608d64388167a3b37a3ea5de3.