Replace the older type with the newer one.
Serialize a copy of auth_info when handling deferred generation,
so that we have a lossless representation of that state when
we eventually process the request. That doesn't change really
anything today, but will enable more granular ACL checks in
the future.
Pass the auth_info through to the http_message_generated and
xfer_message_received events to enable more granular access
control policies to be scripted.