Merge with 3.3, issue #17047: remove doubled words added in 3.3,

as reported by Serhiy Storchaka and Matthew Barnett.

diff --cc Doc/library/unittest.mock.rst
Simple merge

diff --cc Lib/email/_header_value_parser.py
Simple merge

diff --cc Lib/tkinter/__init__.py
Simple merge

diff --cc Lib/unittest/mock.py
Simple merge

diff --cc Modules/socketmodule.c
Simple merge