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/random.rst b/Doc/library/random.rst
index 4306911..e18b217 100644
--- a/Doc/library/random.rst
+++ b/Doc/library/random.rst
@@ -1,19 +1,16 @@
-
 :mod:`random` --- Generate pseudo-random numbers
 ================================================
 
 .. module:: random
    :synopsis: Generate pseudo-random numbers with various common distributions.
 
+**Source code:** :source:`Lib/random.py`
+
+--------------
 
 This module implements pseudo-random number generators for various
 distributions.
 
-.. seealso::
-
-   Latest version of the `random module Python source code
-   <http://svn.python.org/view/python/branches/release27-maint/Lib/random.py?view=markup>`_
-
 For integers, uniform selection from a range. For sequences, uniform selection
 of a random element, a function to generate a random permutation of a list
 in-place, and a function for random sampling without replacement.