The third and final doc-string sweep by Ka-Ping Yee.

The attached patches update the standard library so that all modules
have docstrings beginning with one-line summaries.

A new docstring was added to formatter.  The docstring for os.py
was updated to mention nt, os2, ce in addition to posix, dos, mac.
diff --git a/Lib/repr.py b/Lib/repr.py
index 6376a14..0827428 100644
--- a/Lib/repr.py
+++ b/Lib/repr.py
@@ -1,4 +1,4 @@
-# Redo the `...` (representation) but with limits on most sizes.
+"""Redo the `...` (representation) but with limits on most sizes."""
 
 import string