ceilometer is going to want to subscribe several worker processes
to the notifications.info topic queue. The pool of workers needs
to be assured of receiving all messages, without interference from
other clients listening for notifications. The TopicConsumer
class always assumes the topic and queue name should be the same,
but in the ceilometer case we want to use a separate named queue
with a different name. The only parameter that cannot be
controlled by the user of TopicConsumer is the queue name,
so this change adds the ability to set the queue name.
Change-Id: I41a525de2fd855ca30c24fafcfbfefd6ab615dd7
3ff328d177