Merged revisions 77169 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/trunk

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  r77169 | benjamin.peterson | 2009-12-30 21:17:18 -0600 (Wed, 30 Dec 2009) | 2 lines

  add a --with-system-expat option to build pyexpat against the system's lib #7609
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