auth_token: Various updates, see below. * Defer to usermanager when testing the password * Because of this, don't assume the realm is available when verifying the token * Fix linting errors By using the `usermanager`, other modules can now ask the user manager to verify token credentials.

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);