Fix the "clusteredentity" tutorial for JBoss-5 GA

The clusteredentity tutorial, through its persistence.xml is currently configured to use:

<properties>
<property name="hibernate.cache.provider_class" value="org.jboss.ejb3.entity.TreeCacheProviderHook"/>
<property name="hibernate.treecache.mbean.object_name" value="jboss.cache:service=EJB3EntityTreeCache"/>
<property name="hibernate.hbm2ddl.auto" value="create-drop"/>
</properties>

These do not work on JBoss-5.0 GA. Need to fix this and other related configurations appropriately.