OPENJPA-2321: Synchronizing logging output stream causes deadlock when used some JDK LogManger derivative - back ported to 2.1.x Pinaki's trunk changes.

git-svn-id: https://svn.apache.org/repos/asf/openjpa/branches/2.1.x@1434944 13f79535-47bb-0310-9956-ffa450edef68