Fix permgen exhaustion due to classloader memory leak across server refresh. http://code.google.com/p/google-web-toolkit/issues/detail?id=5486 -Explicitly call destroy() on the WebAppClassLoader -Restart the server, not just the WebAppContext, on refresh -Do a nasty hack to force unload JDBC drivers loaded in the WebAppClassLoader -Port Tomcat's JreMemoryLeakPreventionListener Review at http://gwt-code-reviews.appspot.com/1097801 Review by: rchandia@google.com git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@9214 8db76d5a-ed1c-0410-87a9-c151d255dfc7