Messages - 3.1.3. "response_type=code [id_]token" case doesn't follow OAuth flow.

[hideki nara]

"response_type=code" follows the OAuth flow.

But,

"response_type=code id_token" doesn't.

[[http://openid.bitbucket.org/openid-connect-standard-1_0.html#retrieving_code_token | All cases]] should be described here.

[John Bradley]

We need to reference the response type registration spec.

[John Bradley]

fixed