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/poplib.rst b/Doc/library/poplib.rst
index e5f693d..8456304 100644
--- a/Doc/library/poplib.rst
+++ b/Doc/library/poplib.rst
@@ -1,4 +1,3 @@
-
:mod:`poplib` --- POP3 protocol client
======================================
@@ -9,6 +8,10 @@
.. index:: pair: POP3; protocol
+**Source code:** :source:`Lib/poplib.py`
+
+--------------
+
This module defines a class, :class:`POP3`, which encapsulates a connection to a
POP3 server and implements the protocol as defined in :rfc:`1725`. The
:class:`POP3` class supports both the minimal and optional command sets.