Rename copy_reg module to copyreg.
Updated documentation.
Merged revisions 63042 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk

........
  r63042 | alexandre.vassalotti | 2008-05-11 04:25:28 -0400 (Sun, 11 May 2008) | 5 lines

  Added module stub for copy_reg renaming in 3.0.
  Renamed copy_reg to copyreg in the standard library, to avoid
  spurious warnings and ease later merging to py3k branch. Public
  documentation remains intact.
........
diff --git a/Doc/library/pickle.rst b/Doc/library/pickle.rst
index ff3d918..c3b9c8f 100644
--- a/Doc/library/pickle.rst
+++ b/Doc/library/pickle.rst
@@ -524,7 +524,7 @@
 and calls :meth:`__reduce__`.
 
 An alternative to implementing a :meth:`__reduce__` method on the object to be
-pickled, is to register the callable with the :mod:`copy_reg` module.  This
+pickled, is to register the callable with the :mod:`copyreg` module.  This
 module provides a way for programs to register "reduction functions" and
 constructors for user-defined types.   Reduction functions have the same
 semantics and interface as the :meth:`__reduce__` method described above, except
@@ -775,7 +775,7 @@
 
 .. seealso::
 
-   Module :mod:`copy_reg`
+   Module :mod:`copyreg`
       Pickle interface constructor registration for extension types.
 
    Module :mod:`shelve`