notification options in quantum.conf is not self explained

the right ones should be:
# ============ Notification System Options =====================

# Notifications can be sent when network/subnet/port are create, updated or deleted.
# There are three methods of sending notifications: logging (via the
# log_file directive), rpc (via a message queue) and
# noop (no notifications sent, the default)

# Notification_driver can be defined multiple times
# Do nothing driver
# notification_driver = quantum.openstack.common.notifier.no_op_notifier
# Logging driver
# notification_driver = quantum.openstack.common.notifier.log_notifier
# RPC driver
# notification_driver = quantum.openstack.common.notifier.rabbit_notifier

# default_notification_level is used to form actual topic names or to set logging level
# default_notification_level = INFO

# default_publisher_id is a part of the notification payload
# host = myhost.com
# default_publisher_id = $host

# Defined in rabbit_notifier for rpc way, can be comma separated values.
# The actual topic names will be %s.%(default_notification_level)s
# notification_topics = notifications

Fix proposed to branch: master
Review: https://review.openstack.org/13695

Reviewed: https://review.openstack.org/13695
Committed: http://github.com/openstack/quantum/commit/4e5d904d2e9dc51971348fccb698d295affec96a
Submitter: Jenkins
Branch: master

commit 4e5d904d2e9dc51971348fccb698d295affec96a
Author: gongysh <email address hidden>
Date: Wed Sep 26 16:48:18 2012 +0800

    clean notification options in quantum.conf.

    Bug #1056637

    Change-Id: I9d9002d3dfbbfa94224bc6ed9dc1a7f5207fb563