Merged revisions 86794,86798,86801 via svnmerge from

Merged revisions 86794,86798,86801 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/py3k

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  r86794 | georg.brandl | 2010-11-26 12:50:13 +0100 (Fr, 26 Nov 2010) | 1 line

  #10526: fix typo.
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  r86798 | georg.brandl | 2010-11-26 13:05:48 +0100 (Fr, 26 Nov 2010) | 1 line

  #10420: fix docs of bdb.effective().
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  r86801 | georg.brandl | 2010-11-26 13:12:14 +0100 (Fr, 26 Nov 2010) | 1 line

  Better example for os.system(): do not change the system time.
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