Fix ALF-4118 - PersonServiceImpl - prevent creation of duplicate people

- add validation to prevent direct creation / deletion (if using people container)
- should fix other possible inconsistencies with personCache
- add unit tests
- minor cleanup

git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@23038 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/service/cmr/security/PersonService.java

@@ -184,6 +184,14 @@ public interface PersonService
      */
     @Auditable(parameters = {"userName"})
     public void deletePerson(String userName);
+    
+    /**
+     * Delete the person identified by the given ref.
+     * 
+     * @param personRef
+     */
+    @Auditable(parameters = {"personRef"})
+    public void deletePerson(NodeRef personRef);
 
     /**
      * Get all the people we know about.