Remove period from end of headings.

Doc/library/cgi.rst

-
-:mod:`cgi` --- Common Gateway Interface support.
-================================================
+:mod:`cgi` --- Common Gateway Interface support
+===============================================
 
 .. module:: cgi
    :synopsis: Helpers for running Python scripts via the Common Gateway Interface.

Doc/library/contextlib.rst

-
-:mod:`contextlib` --- Utilities for :keyword:`with`\ -statement contexts.
-=========================================================================
+:mod:`contextlib` --- Utilities for :keyword:`with`\ -statement contexts
+========================================================================
 
 .. module:: contextlib
    :synopsis: Utilities for with-statement contexts.

Doc/library/ctypes.rst

-
-:mod:`ctypes` --- A foreign function library for Python.
-========================================================
+:mod:`ctypes` --- A foreign function library for Python
+=======================================================
 
 .. module:: ctypes
    :synopsis: A foreign function library for Python.

Doc/library/curses.panel.rst

-
-:mod:`curses.panel` --- A panel stack extension for curses.
-===========================================================
+:mod:`curses.panel` --- A panel stack extension for curses
+==========================================================
 
 .. module:: curses.panel
    :synopsis: A panel stack extension that adds depth to  curses windows.

Doc/library/pickletools.rst

-
-:mod:`pickletools` --- Tools for pickle developers.
-===================================================
+:mod:`pickletools` --- Tools for pickle developers
+==================================================
 
 .. module:: pickletools
    :synopsis: Contains extensive comments about the pickle protocols and pickle-machine

Doc/library/platform.rst

-
-:mod:`platform` ---  Access to underlying platform's identifying data.
-======================================================================
+:mod:`platform` ---  Access to underlying platform's identifying data
+=====================================================================
 
 .. module:: platform
    :synopsis: Retrieves as much platform identifying data as possible.