[docs] Python 2.6.5 threading.Event.wait()

[Andrew Trusty]

Just spent a couple hours debugging some code because the
threading.Event.wait() documentation said it returned the internal
flag when it always returns None.  I just noticed that there is an
addendum that says this was behavior that was changed in 2.7 but since
these are the 2.6.5 docs it would be a lot less confusing if it first
said that it always returns None and then said that in 2.7 it will
return the internal flag.

http://docs.python.org/library/threading.html#threading.Event.wait

Andrew