Blocked revisions 81020 via svnmerge

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  r81020 | mark.dickinson | 2010-05-09 10:30:06 +0100 (Sun, 09 May 2010) | 3 lines

  Issue #8644:  Improve accuracy of timedelta.total_seconds method.
  (Backport of r80979 to py3k.)  Thanks Alexander Belopolsky.
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