Blocked revisions 81957 via svnmerge

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  r81957 | mark.dickinson | 2010-06-12 19:50:34 +0100 (Sat, 12 Jun 2010) | 5 lines

  Issue #8469:  Add standard sizes to table in struct documentation; additional
  clarifications and documentation tweaks.

  Backport of revisions 81955-81956 from py3k.
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