Advertise our relying party XRDS document

Some OpenID providers, e.g. Yahoo!'s, want this document to
validate the information coming as part of the OpenID login
request we send them.  Its apparently part of the OpenID 2.0
specification, but I wasn't aware of it until today.

Change-Id: I94b72a4825271b37023a73d59a7aed1f5ab18341
Signed-off-by: Shawn O. Pearce <sop@google.com>
3 files changed