Removed dead code and various cleaning

Author: saro0h

Compiler/CheckCircularReferencesPass.php

@@ -26,7 +26,6 @@
  */
 class CheckCircularReferencesPass implements CompilerPassInterface
 {
-    private $currentId;
     private $currentPath;
     private $checkedNodes;
 
@@ -41,7 +40,6 @@ public function process(ContainerBuilder $container)
 
         $this->checkedNodes = array();
         foreach ($graph->getNodes() as $id => $node) {
-            $this->currentId = $id;
             $this->currentPath = array($id);
 
             $this->checkOutEdges($node->getOutEdges());