Merge branch '2.3' into 2.4

* 2.3:
  Update twig_reference.rst
  Update version in Rework your Patch section

Author: weaverryan

contributing/code/patches.rst

@@ -364,7 +364,7 @@ Rework your Patch
 
 Based on the feedback on the pull request, you might need to rework your
 patch. Before re-submitting the patch, rebase with ``upstream/master`` or
-``upstream/2.1``, don't merge; and force the push to the origin:
+``upstream/2.3``, don't merge; and force the push to the origin:
 
 .. code-block:: bash
 

reference/twig_reference.rst

@@ -5,7 +5,7 @@ Symfony2 Twig Extensions
 ========================
 
 Twig is the default template engine for Symfony2. By itself, it already contains
-a lot of build-in functions, filters, tags and tests (`http://twig.sensiolabs.org/documentation`_
+a lot of built-in functions, filters, tags and tests (`http://twig.sensiolabs.org/documentation`_
 then scroll to the bottom).
 
 Symfony2 adds more custom extension on top of Twig to integrate some components