ensure no messages get stuck inflight on pooled active consumers. A little tricky to get to the bottom of exactly why the consumer remains. it is visible in jmx on occasion when it hangs. prefetch=0 avoids any inflight messages, may need a revisit

git-svn-id: https://svn.apache.org/repos/asf/activemq/trunk@1442761 13f79535-47bb-0310-9956-ffa450edef68