[Openid-specs-ab] Google's OpenID Connect service

[Tim Bray]

We’re getting ready to rev our OIDC service, which was built against a
long-out-of-date draft, with the version described in
https://docs.google.com/document/d/1LZ8hPtZ-6llgi2zy9FJ9k1X0BbMra_kJuLS9wO4wA8w/edit
- the service is actually live on our prod servers, feel free to bash
away at it.

We believe this to be in sync with what we believe will be the content
of the forthcoming OIDC Implementors’ Drafts; we will treat
inconsistencies as bugs.  Our hope is that the protocol doesn’t change
materially from here on in.

We have been offering the public a “Login with OAuth 2.0” service for
some time now, and the plan is for this to replace that in the near
future.  -Tim