[development doc updates]

[Fred L. Drake]

The development version of the documentation has been updated:

    http://python.sourceforge.net/devel-docs/

Removed reference material for some long-obsolete Mac OS modules that have
not been included in recent versions of MacPython.

Added material on the proposed C API for weak reference objects; see the
Python/C API Reference Manual:

    http://python.sourceforge.net/devel-docs/api/weakref-objects.html