merged branch fabpot/twig-deprecated-features (PR #580)

This PR was merged into the 2.2 branch.

Discussion
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Twig deprecated features

see symfony/symfony#8675

Commits
-------

35a5826 updated demo code to use the non-deprecated features of Twig

Author: fabpot

src/Acme/DemoBundle/Twig/Extension/DemoExtension.php

@@ -25,7 +25,7 @@ public function setController($controller)
     public function getFunctions()
     {
         return array(
-            'code' => new \Twig_Function_Method($this, 'getCode', array('is_safe' => array('html'))),
+            new \Twig_SimpleFunction('code', array($this, 'getCode'), array('is_safe' => array('html'))),
         );
     }