Fix warning.

git-svn-id: https://svn.apache.org/repos/asf/activemq/activemq-apollo/trunk@1446393 13f79535-47bb-0310-9956-ffa450edef68
Add a DLQ stress tests.

git-svn-id: https://svn.apache.org/repos/asf/activemq/activemq-apollo/trunk@1446394 13f79535-47bb-0310-9956-ffa450edef68
When messages were being moved to the DLQ they would occasionally get into a bad state.  We now handle the case were a swap out gets canceled much better.

git-svn-id: https://svn.apache.org/repos/asf/activemq/activemq-apollo/trunk@1446395 13f79535-47bb-0310-9956-ffa450edef68