Py_Main() can again be called after Py_Initialize(), as in Python
3.6. The new configuration is ignored, except of
_PyMainInterpreterConfig.argv which is used to update sys.argv.

Increase the timeout: give timeout x 4 instead of timeout x 2 to
threads to wait until the Event is set, but reduce the sleep from 500
ms to 250 ms. So the test should be more reliable and faster!

On Windows, sometimes test_signal.test_warn_on_full_buffer() fails to
fill the socketpair buffer. In that case, the C signal handler
succeed to write into the socket, it doesn't log the expected send
error, and so the test fail.

On Windows, the test now uses a timeout of 50 ms to fill the
socketpair buffer to fix this race condition.

Other changes:

* Begin with large chunk size to fill the buffer to speed up the
  test.
* Add error messages to assertion errors to more easily identify
  which assertion failed.
* Don't set the read end of the socketpair as non-blocking.

test_signal.test_socket(): On Windows, sometimes even if the C signal handler
succeed to write the signal number into the write end of the socketpair, the
test fails with a BlockingIOError on the non-blocking read.recv(1) because the
read end of the socketpair didn't receive the byte yet.

Fix the race condition on Windows by setting the read end as blocking.

bpo-32430: Rename Modules/Setup.dist to Modules/Setup

Remove the necessity to copy the former manually to the latter when updating the local source tree.

Replace deprecated inspect.getfullargspec() with inspect.signature().

Check that the size of the varnames tuple is enough at least for all arguments.

`_PyUnicode_TransformDecimalAndSpaceToASCII()` missed trailing NUL char.
It caused buffer overflow in `_Py_string_to_number_with_underscores()`.

This bug is introduced in 9b6c60cb.

* Add test capturing failure.
* Honor newlines as present in the original file.

The test failed on AMD64 Debian root 3.x buildbot because the busy
loop of 100 ms only increased time.thread_time() by 19.9 ms which is
smaller than 20 ms. Modify the test to tolerate a delta of at least
15 ms instead of 20 ms.

It was added in test_functools at 445f1b35.

This code does not appear to be used anywhere in the python code base.
The use was removed in eb81795d.

Change test_logging.SMTPHandlerTest timeout from 8 seconds to 1
minute. The test failed randomly on the slow x86 Gentoo Refleaks 3.7
buildbot.

Dataclasses: Fix example on 30.6.8, add method should receive a list rather than an integer. (GH-8038)

Change example function to append rather than add lists.

The ValueError message ends with a period.

Many users won't realise the implications the OpenSSL 1.0.2
minimum version requirement has when it comes to Ubuntu
14.04 and Debian 8, so expand on that in the platform support
section.

Also explicitly note the non-ASCII-based locale requirement for
full Unicode text handling support on non-Windows systems.

Contributed by Bradley Laney.