Deal with the "Allow SE.com/SO.com/M.SE.com to use this openid" page

[Manishearth]

Since the SE openid is integrated, on some sites there is no confirmation message unless you enter it as a custom openid. We're doing the latter here, so we should probably automatically do the confirmation, OR switch to the built in mechanism (which is a bit roundabout)

Related: #8 as well

[banksJeremy]

This was supposed to be handled by #18, which successfully authenticated my account the first time it logged in to SE.com. Maybe I broke it at some point.

[Manishearth]

Oh, I remember now. I wonder what issue red-green is having then.

[Filnor]

Invalid by now as OpenID is now replaced.