Remove sys.exc_clear()

pep-3100.txt

@@ -237,7 +237,7 @@ To be removed:
   not thread-safe; use ``sys.exc_info()`` or an attribute
   of the exception [2]_ [11]_ [#sys-module]_ [done]
 * ``sys.exc_clear``: Python 3's except statements provide the same
-  functionality [24]_ [#pep3110]_ [#sys-module]_
+  functionality [24]_ [#pep3110]_ [#sys-module]_ [done]
 * ``array.read``, ``array.write`` [#array-module]_
 * ``operator.isCallable`` : ``callable()`` built-in is being removed
   [#operator-module]_ [#remove-operator-funcs]_ [done]