[docs] Different documentation for identical methods (issue 17858)

[ezio.melotti at gmail.com]

http://bugs.python.org/review/17858/diff/8017/Doc/library/threading.rst
File Doc/library/threading.rst (right):

http://bugs.python.org/review/17858/diff/8017/Doc/library/threading.rst#newcode371
Doc/library/threading.rst:371: necessary waiting until it is released by
another thread (only one thread at a
These lines are too long.

http://bugs.python.org/review/17858/diff/8017/Doc/library/threading.rst#newcode377
Doc/library/threading.rst:377: unconditionally as above.
This paragraph could be simplified.
"If *blocking* is ``False``, the lock is acquired only if it can be
acquired; if it's ``True``, the lock is acquired unconditionally as
above."

http://bugs.python.org/review/17858/