Backport source links from 3.x.

Existing links have been updated to use the new reST role.  In some
files, I have also made cosmetic changes to the header.
diff --git a/Doc/library/fnmatch.rst b/Doc/library/fnmatch.rst
index cb1fa10..4911980 100644
--- a/Doc/library/fnmatch.rst
+++ b/Doc/library/fnmatch.rst
@@ -1,4 +1,3 @@
-
 :mod:`fnmatch` --- Unix filename pattern matching
 =================================================
 
@@ -10,6 +9,10 @@
 
 .. index:: module: re
 
+**Source code:** :source:`Lib/fnmatch.py`
+
+--------------
+
 This module provides support for Unix shell-style wildcards, which are *not* the
 same as regular expressions (which are documented in the :mod:`re` module).  The
 special characters used in shell-style wildcards are:
@@ -34,10 +37,6 @@
 a period are not special for this module, and are matched by the ``*`` and ``?``
 patterns.
 
-.. seealso::
-
-   Latest version of the `fnmatch Python source code
-   <http://svn.python.org/view/python/branches/release27-maint/Lib/fnmatch.py?view=markup>`_
 
 .. function:: fnmatch(filename, pattern)
 
@@ -95,4 +94,3 @@
 
    Module :mod:`glob`
       Unix shell-style path expansion.
-