Revert "Added new tag"

This reverts commit 26500fb.

Author: weaverryan

reference/twig_reference.rst

@@ -134,9 +134,6 @@ Filters
 Tags
 ----
 
-.. versionadded:: 2.3
- The stopwatch tag was added in Symfony 2.3
-
 +---------------------------------------------------+--------------------------------------------------------------------+
 | Tag Syntax | Usage |
 +===================================================+====================================================================+
@@ -153,9 +150,6 @@ Tags
 | ``{% trans_default_domain language %}`` | This will set the default domain for message catalogues in the |
 | | current template |
 +---------------------------------------------------+--------------------------------------------------------------------+
-| ``{% stopwatch name %}...{% endstopwatch %}`` | This will time the run time of the code inside it and put that on |
-| | the timeline of the WebDeveloperBundle. |
-+---------------------------------------------------+--------------------------------------------------------------------+
 
 Tests
 -----