Merged revisions 87710 via svnmerge from

Merged revisions 87710 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/py3k

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  r87710 | gregory.p.smith | 2011-01-03 13:06:12 -0800 (Mon, 03 Jan 2011) | 4 lines

  issue6643 - Two locks held within the threading module on each thread instance
  needed to be reinitialized after fork().  Adds tests to confirm that they are
  and that a potential deadlock and crasher bug are fixed (platform dependant).
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This required a bit more fiddling for 2.x as __block and __started are __
private as well as the __started Event's __cond.  A new "private"
_reset_internal_locks() method is added to Thread and _Event objects to
address this.