Issue #21629: Fix Argument Clinic's "--converters" feature.
Issue #21629: Merge from 3.4.
#21693 - Fix the broken link for pylons project.
merge from 3.4
#19662: add decode_data to smtpd so you can get at DATA in bytes form.

Otherwise smtpd is restricted to 7bit clean data, since even if the
incoming data is actually utf-8, it will often break things to decode
it before parsing the message.

Patch by Maciej Szulik, with some adjustments (mostly the warning
support).
#19662: Eliminate warnings in other test modules that use smtpd.

Eventually these will want to convert to decode_data=False, I think.
#14758: add IPv6 support to smtpd.

Patch by Milan Oberkirch.
#19840: Add copy_function to shutil.move.

Patch by Claudiu Popa.
#14758: Need to specify the desired socket type in the getaddrinfo call.

This worked by accident on Linux because the SOCK_STREAM was returned
first, but on the FreeBSD the SOCK_DGRAM is first in the list.
Fix doc build warning
#14758: Fix the fix (fix getaddrinfo in mock_socket)

I forgot to run all the affected tests when I fixed smtpd.
Eliminate DeprecationWarning in test_concurrent_futures.
Issue #21713: Fix typo in a comment.  Found by Joseph Shen.
Closes #21713: Merge with 3.4
Suppress a couple more DeprecationWarnings in the test suite.
Issue #12387: Add missing upper(lower)case versions of default Windows key
bindings for Idle so Caps Lock does not disable them. Patch by Roger Serwy.
Merge with 3.4