Merged revisions 83400 via svnmerge from

Merged revisions 83400 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/py3k

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  r83400 | mark.dickinson | 2010-08-01 11:41:49 +0100 (Sun, 01 Aug 2010) | 7 lines

  Issue #9416: Fix some issues with complex formatting where the
  output with no type specifier failed to match the str output:

    - format(complex(-0.0, 2.0), '-') omitted the real part from the output,
    - format(complex(0.0, 2.0), '-') included a sign and parentheses.
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