Add posix.lchown()

Doc/whatsnew/whatsnew23.tex

@@ -679,8 +679,7 @@ convert between radians and degrees.  Other functions in the
 \function{math.sin()} and \function{math.cos()} have always required
 input values measured in radians. (Contributed by Raymond Hettinger.)
 
-\item Three new functions, \function{getpgid()}, \function{killpg()},
-and \function{mknod()}, were added to the \module{posix} module that
+\item Four new functions, \function{getpgid()}, \function{killpg()}, \function{lchown()}, and \function{mknod()}, were added to the \module{posix} module that
 underlies the \module{os} module.  (Contributed by Gustavo Niemeyer
 and Geert Jansen.)