[XML-SIG] Upgrading Expat

[Martin v. Loewis]

I just imported Expat 1.2 into the PyXML tree, and updated the pyexpat
module to expose the new handlers supported by Expat. Unfortunately,
there is no version number in the Expat headers, so anybody compiling
the expat module must now what the expat version is. For PyXML,
setup.py can always know what the Expat version is we ship; for Python
proper, it would default to 1.1 unless specified otherwise.

Regards,
Martin