https://issues.apache.org/jira/browse/AMQ-4643 - ensure handled ioexceptions are not propagated back to client when broker or transports are shutdown. additional tests existing tests refactored to reflect new determinism. IOException handler now throws SuppressReplyException which is trapped by the transport connector. If store exception need to be processes by the client, for immediate response rather than failover reconnect, then the ioexception handler should be configured to ignoreAllErrors

git-svn-id: https://svn.apache.org/repos/asf/activemq/trunk@1508602 13f79535-47bb-0310-9956-ffa450edef68