All this does is confirm that Tix is available on Windows, which should
always be the case (if _tkinter itself is available).

Patch by samwyse, completed by Arnon Yaari, and reviewed by
Martin Panter.

Reviewed by Maciej Szulik.

doc.  Remove obsolete example from FAQ.  Patch by Martin Panter.

This defaults to True in the compat32 policy for backward compatibility,
but to False for all new policies.

Patch by Milan Oberkirch, with a few tweaks.

This could use more edge case tests, but the basic functionality is tested.
(Note that this changeset does not add tailored support for the RFC 6532
message/global MIME type, but the email package generic facilities will handle
it.)

Reviewed by Maciej Szulik.

Also fix a couple other ignored PCbuild directories in .gitignore

Patch by Abhilash Raj.

Patch by Milan Oberkirch.

Made test_pprint discoverable.

Made test_pprint discoverable.

When not using decode_data=True, smtpd may provide keyword arguments to the
process_message user-implemented method.  This doc update is intended to make
it clear that arbitrary keywords must be supported, so that we can add
additional features in the future by just adding keywords to the
process_message call.

Initial patch by Milan Oberkirch.

assertWarnsRegex() checks now emits a deprecation warning when callable is
None or keyword arguments except msg is passed in the context manager mode.