Exception for shutdingdown the database is now catched in the shutdown
methode of the persistencefacade. persistence.xml is nolonger in
developer mode... meaning the database tables aren't any longer changed
automatically and reset at start. Modiefied both test, so that the no
longer catch the exception from the shutdown, added a start/shutdown
test to persistencetest. Fixed ProxyUserManagerTest, so that the
database get's not startet and stopped before every single test.
Remember shutdown and start of the db IS NOT THREADSAFE.