Merge branch '3.4' into 4.2

* 3.4:
  Added php opening tag to sample controller

Author: javiereguiluz

page_creation.rst

@@ -44,6 +44,7 @@ Suppose you want to create a page - ``/lucky/number`` - that generates a lucky (
 random) number and prints it. To do that, create a "Controller class" and a
 "controller" method inside of it::
 
+    <?php
     // src/Controller/LuckyController.php
     namespace App\Controller;