finish openid

finish openid

Added some code to make finishing the OpenID login work.

Changed the OID storage so that there's a "canonical" URL and a
display URL. This is because of i-names, which is annoying.

If the login succeeds, we try to find a local user associated with the
canonical URL. If they don't exist, we let the user either create a
new account, or login to an existing account and connect to it.

A totally unrelated change is that the DB engine now uses InnoDB.

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