Merged revisions 74078 via svnmerge from

Merged revisions 74078 via svnmerge from
svn+ssh://pythondev@www.python.org/python/branches/py3k

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  r74078 | mark.dickinson | 2009-07-18 15:41:42 +0100 (Sat, 18 Jul 2009) | 5 lines

  Issue #6431: Fix Fraction comparisons to return NotImplemented when
  the Fraction type doesn't know how to handle the comparison without
  loss of accuracy.  Also, make sure that comparisons between Fractions
  and float infinities or nans do the right thing.
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