TODO

* link queues/topics to their apps (requires TB changes)
* see how backstage behaves in a cluster 
* allow resending DLQ and ExpiryQueue messages (requires replacing the external (client) queuebrowser with one based off of the mbean listMessages)
* store failure backtraces for jobs/tasks in TorqueBox, and display here  (requires TB changes)
* improve test coverage
* add stats collection, with memory usage and other bits? ruby runtime stats?