Message 282651 - Python tracker

This last patch (make_doctest_ok.patch) makes all doctests pass (Sphinx 1.5, Python 3.6). Before applaying the patch there are 466 failures in 2096 tests, and after we have more tests (2414) and 0 failures. Actually, sometimes 3 tests fail in Doc/library/unittest.mock-examples.rst, but I did not get why :/