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/fractions.rst b/Doc/library/fractions.rst
index 1ca9a9c..4d10cbd 100644
--- a/Doc/library/fractions.rst
+++ b/Doc/library/fractions.rst
@@ -1,4 +1,3 @@
-
:mod:`fractions` --- Rational numbers
=====================================
@@ -8,6 +7,9 @@
.. sectionauthor:: Jeffrey Yasskin <jyasskin at gmail.com>
.. versionadded:: 2.6
+**Source code:** :source:`Lib/fractions.py`
+
+--------------
The :mod:`fractions` module provides support for rational number arithmetic.