Prevent unnecessary on close of an objectstore that hasn't written to the log.
Deregister ShutdownHook from JVM on webapp undeploy - allows WebappClassLoader to be garbage collected preventing PermGen memory leak. Clean up shutdown procedure to rely more on ShutdownHook.
Close connection used to fetch database version.
Merge pull request #894 from rnsmith/tomcat-leak

Fix webapp PermGen memory leak