now derived from AbstractNodeServiceImpl to make policy awareness easier.
Moved addDefaultPropertyValues from DbNodeServiceImpl to
AbstractNodeServiceImpl so AVMNodeService can use it. A fix for an
NPE that showed up in stress test.
git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/BRANCHES/WCM-DEV2/root@3603 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261