Added missing callbacks to AVMNodeService. This makes things slow.

Have to do something about that.
Added getPaths call to AVMService.  Retrieves all possible paths to a node.
Need to do timing tests.
I believe, the 6th version of a Pair template class. This one's public and 
perhaps when we have time we could use it in place of all the inner class
implementations.


git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/BRANCHES/WCM-DEV2/root@3964 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/repo/avm/VersionRootDAO.java

@@ -53,6 +53,13 @@ public interface VersionRootDAO
      */
     public VersionRoot getByVersionID(AVMStore store, int id);
     
+    /**
+     * Get one from its root.
+     * @param root The root to match.
+     * @return The version root or null.
+     */
+    public VersionRoot getByRoot(AVMNode root);
+    
     /**
      * Get the version of a store by dates.
      * @param store The store.