[docs] Fix internal references for concurrent modules (issue 18757)

[ezio.melotti at gmail.com]

LGTM.


http://bugs.python.org/review/18757/diff/8955/Doc/library/multiprocessing.rst
File Doc/library/multiprocessing.rst (right):

http://bugs.python.org/review/18757/diff/8955/Doc/library/multiprocessing.rst#newcode1071
Doc/library/multiprocessing.rst:1071: The :meth:`wait_for
<threading.Condition.wait_for>` method was added.
Isn't this equivalent to :meth:`~threading.Condition.wait_for`? or does
this include "Condition." too?

http://bugs.python.org/review/18757/diff/8955/Doc/library/multiprocessing.rst#newcode1478
Doc/library/multiprocessing.rst:1478: The :meth:`wait_for
<threading.Condition.wait_for>` method was added.
Ditto.

http://bugs.python.org/review/18757/diff/8955/Doc/library/select.rst
File Doc/library/select.rst (right):

http://bugs.python.org/review/18757/diff/8955/Doc/library/select.rst#newcode336
Doc/library/select.rst:336: :meth:`~~io.IOBase.fileno` method that
returns an integer.
Is the double ~ a typo or some syntax that I don't know?

http://bugs.python.org/review/18757/