Blocked revisions 62195 via svnmerge

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  r62195 | gregory.p.smith | 2008-04-07 01:11:17 +0200 (Mon, 07 Apr 2008) | 10 lines

  Make file objects as thread safe as the underlying libc FILE* implementation.
  close() will now raise an IOError if any operations on the file object
  are currently in progress in other threads.

  Most code was written by Antoine Pitrou (pitrou).  Additional testing,
  documentation and test suite cleanup done by me (gregory.p.smith).

  Fixes issue 815646 and 595601 (as well as many other bugs and
  references to this problem dating back to the dawn of Python).
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