Distributed amqp nodes version

* Add option -l (log traces for publishing)
* Add options -c (publish confirms),
  -u (amqp user), -p (amqp pass), -n (amqp nodes)
* Make publish multi-threaded
* Add SIGINT for threads
* Add license Apache 2.0 header, contributors & sources lists

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>