The concept of what was unexpected was typically defined as "some
depencendy wasn't installed", which isn't unexpected at all as it's
totally optional. Since it confuses new contributors as they think
something is wrong with their installation it seems sensible to get
rid of the concept.

This change also adds the concept of optional tests that are required
to work on a specific platform(s) (e.g. test_winreg on Windows). This
should help catch compile issues instead of a test being blindly
skipped even when it should have run.

The skipped test list in the future can also print out the reason for
being skipped to make it more obvious as to why the skipping occurred.

Patch by Serhiy Storchaka.

Patch by Serhiy Storchaka.

Patch by Serhiy Storchaka.

Patch by Serhiy Storchaka.

Patch by Serhiy Storchaka.

the user to import any parent packages.

MERGE: Closes #16461: Wave library should be able to deal with 4GB wav files, and sample rate of 44100 Hz.

MERGE: Closes #16461: Wave library should be able to deal with 4GB wav files, and sample rate of 44100 Hz.

global import lock after forking.

Also merged two duplicate sections of Tools/Demos.

It had not been updated since May 2008 (6 months before Python 3 was
released!).

This now removes any special editor support by python-dev, alleviating
those burdens.

They had become extremely stale (the script to generate the file was
Python 2 compatible!). Plus the community took the work and made
improvements that are available on www.vim.org.

If you want to update Vim's runtime files to the latest available,
follow the instructions at http://www.vim.org/runtime.php .

Issue #16469: Fraction(float('nan')) and Fraction(float('inf')) now raise ValueError and OverflowError (resp.), not TypeError.