Add 'see also' section pointing to the PEP

Doc/whatsnew/whatsnew24.tex

@@ -55,6 +55,11 @@ root:*:0:0:System Administrator:/var/root:/bin/tcsh
   ...
 \end{verbatim}
 
+\begin{seealso}
+\seepep{322}{Reverse Iteration}{Written and implemented by Raymond Hettinger.}
+
+\end{seealso}
+
 
 %======================================================================
 \section{Other Language Changes}