[Config] Renaming the NodeBuilder::addNodeBuilder() to simply NodeBuilder::nodeBuilder() to be consistent with the other names: node(), arrayNode().

src/Symfony/Component/Config/Definition/Builder/NodeBuilder.php

@@ -115,7 +115,7 @@ class NodeBuilder
      *
      * @return Symfony\Component\DependencyInjection\Configuration\Builder\NodeBuilder This builder node
      */
-    public function addNodeBuilder(NodeBuilder $node)
+    public function nodeBuilder(NodeBuilder $node)
     {
         $node->parent = $this;