Undo the deprecation of _asdict().

Backed out changeset c4ca39bece9d
diff --git a/Doc/library/collections.rst b/Doc/library/collections.rst
index 7063768..96c5aef 100644
--- a/Doc/library/collections.rst
+++ b/Doc/library/collections.rst
@@ -829,9 +829,6 @@
     .. versionchanged:: 3.1
         Returns an :class:`OrderedDict` instead of a regular :class:`dict`.
 
-    .. deprecated:: 3.4
-       Use ``vars(nt)`` or ``nt.__dict__`` instead.
-
 .. method:: somenamedtuple._replace(kwargs)
 
     Return a new instance of the named tuple replacing specified fields with new
@@ -848,8 +845,8 @@
 
     A string with the pure Python source code used to create the named
     tuple class.  The source makes the named tuple self-documenting.
-    It can be printed, executed using :func:`exec`, customized, or saved
-    to a file and imported.
+    It can be printed, executed using :func:`exec`, or saved to a file
+    and imported.
 
     .. versionadded:: 3.3