Upgrade Twig library

inc/lib/Twig/TokenParser/Import.php

@@ -32,13 +32,15 @@ class Twig_TokenParser_Import extends Twig_TokenParser
         $var = new Twig_Node_Expression_AssignName($this->parser->getStream()->expect(Twig_Token::NAME_TYPE)->getValue(), $token->getLine());
         $this->parser->getStream()->expect(Twig_Token::BLOCK_END_TYPE);
 
+        $this->parser->addImportedSymbol('template', $var->getAttribute('name'));
+
         return new Twig_Node_Import($macro, $var, $token->getLine(), $this->getTag());
     }
 
     /**
      * Gets the tag name associated with this token parser.
      *
-     * @param string The tag name
+     * @return string The tag name
      */
     public function getTag()
     {