Added versionadded blocks

Author: wouterj

reference/twig_reference.rst

@@ -17,6 +17,9 @@ There may also be tags in bundles you use that aren't listed here.
 Functions
 ---------
 
+.. versionadded:: 2.1
+    The ``csrf_token``, ``logout_path`` and ``logout_url`` functions were added in Symfony2.1
+
 +----------------------------------------------------+--------------------------------------------------------------------------------------------+
 | Function Syntax                                    | Usage                                                                                      |
 +====================================================+============================================================================================+
@@ -64,6 +67,9 @@ Functions
 Filters
 -------
 
+.. versionadded:: 2.1
+    The ``humanize`` filter was added in Symfony2.1
+
 +---------------------------------------------------------------------------------+-------------------------------------------------------------------+
 | Filter Syntax                                                                   | Usage                                                             |
 +=================================================================================+===================================================================+
@@ -124,6 +130,9 @@ Tags
 Tests
 -----
 
+.. versionadded:: 2.1
+    The ``selectedchoice`` test was added in Symfony2.1
+
 +---------------------------------------------------+------------------------------------------------------------------------------+
 | Test Syntax                                       | Usage                                                                        |
 +===================================================+==============================================================================+