Description of configuration options for notifier

Configuration option = Default value	Description
default_notification_level = INFO	(StrOpt) Default notification level for outgoing notifications
default_publisher_id = $host	(StrOpt) Default publisher_id for outgoing notifications
notification_driver = []	(MultiStrOpt) Driver or drivers to handle sending notifications
notification_topics = notifications	(ListOpt) AMQP topic used for openstack notifications