mod_rest: Support parameters in callback URL
E.g.
rest_callback_url = "http://myapi.example:5000/api/{kind}/{type}"
which results in e.g. requests to /api/message/chat
Allows using path routing in web frameworks for dispatch instead of
having to pick apart the payload to further dispatch it.
module:hook("authentication-success", function (event)
local session = event.session;
local sasl_handler = session.sasl_handler;
session.log("info", "Authenticated with %s", sasl_handler and sasl_handler.selected or "legacy auth");
end);