Update pydoc topic index for Python 3.4.0a2.
Version number bump for Python 3.4.0a2.
Added tag v3.4.0a2 for changeset 9265a2168e2c
Issue 18984:  Remove ._stopped Event from Thread internals.

The fix for issue 18808 left us checking two things to be sure a Thread
was done:  an Event (._stopped) and a mutex (._tstate_lock).  Clumsy &
brittle.  This patch removes the Event, leaving just a happy lock :-)

The bulk of the patch removes two excruciating tests, which were
verifying sanity of the internals of the ._stopped Event after a fork.
Thanks to Antoine Pitrou for verifying that's the only real value
these tests had.

One consequence of moving from an Event to a mutex:  waiters (threads
calling Thread.join()) used to block each on their own unique mutex
(internal to the ._stopped event), but now all contend on the same
mutex (._tstate_lock).  These approaches have different performance
characteristics on different platforms.  I don't think it matters in
this context.
Issue 18752:  Make chain.from_iterable() more visible in the documentation.
Close #18980: Enum doc fixes.  Patch from Elazar Gershuni.
Issue 18301:  The classmethod decorator didn't fit well with the rough-equivalent example code.
merge
merge
Issue 18752:  Make chain.from_iterable() more visible in the documentation.
merge
Docstring typo fix: Arithmentic -> Arithmetic.
Merge docstring typo fix from 3.3
Post-3.4.0a2-release fixups.
Merge.
Minor cleanup of the new scheme for detecting thread termination.

Documented some obscurities, and assert'ed ._stop()'s crucial precondition.
Backed out changeset 1f5a7853680c

Unixy buildbots were failing the thread + fork tests :-(
Another stab at the thread cleanup patch.

Antoine Pitrou found a variation that worked for him on the
thread+fork tests, and added an important

    self._is_stopped = True

to the after-fork code.  I confess I don't know why things passed
before.  But then mixing fork with threads is insane ;-)