an => and

The bug has been fixed 10 months ago:

* https://svnweb.freebsd.org/base?view=revision&revision=321920
* https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=221048

With 3.7+, dictionary are ordered by design.  Configparser still uses
collections.OrderedDict, which is unnecessary.  This updates the module
to use the standard dict implementation by default, and changes the
docs and tests to match.

It wasn't testing functionality.  Now it is (on Linux anyways).

* Document tokenize.generate_tokens()

* Add news file

* Add test for generate_tokens

* Document behaviour around ENCODING token

* Add generate_tokens to __all__

testModeStrings and testTruncateOnWindows were depended on
a file leaked in other tests.

Also improve cleaning up after tests.

With addCleanup() f.close() was executed after tearDown().

In addition to that, mark SSLTransport as "closed" in its "abort()" method to prevent bogus warnings.

Raise TypeError instead of SystemError for unsupported operations.

Previously, the mouse wheel and scrollbar slider moved text by a fixed
number of pixels, resulting in partial lines at the top of the editor
box. The change also applies to the shell and grep output windows,
but not to read-only text views.

* Fix AttributeError (not all SSL exceptions have 'errno' attribute)

* Increase default handshake timeout from 10 to 60 seconds
* Make sure start_tls can be cancelled correctly
* Make sure any error in SSLProtocol gets propagated (instead of just being logged)

The bytes parameter uses big endian.

Fix test_warnings.test_module_globals() when python3 is run with
-Werror.

Homebrew's python is now python3, but travis preinstalls old python2.
So updated Homebrew requires `brew upgrade python` now.

This commit disables auto update and use preinstalled version of Homebrew.

It depended on a global variable set by other tests.

* Prevent spurious message if taking a shortcut
* Fix YAML style
* Disable largefile tests

Separate tests leaked files or were depended on files leaked in other tests.

`writerows()` takes an iterable.

This is a simple grammatical fix correcting "...object whose `__self__` attributes is ..." to "...object whose `__self__` attribute is ...".

Fix typos in code comments: bdb.py and configure.ac.

The difference from before is that the settings are now on the
Highlights tab instead of the Extensions tab and only change one theme
at a time instead of all themes. The default for light themes is black
on light gray, as before. The default for the IDLE Dark theme is white
on dark gray, which better fits the dark theme.

When one starts IDLE from a console and loads a custom theme without
definitions for 'context', one will see a warning message on the console.
To stop the warning, go to Options => Configure IDLE => Highlights,
select the custom theme if not selected already, select 'Code Context',
and select foreground and background colors.

For bpo-32604 I added extra subinterpreter-related tests (see #6914), which caused a few buildbots to crash. This patch fixes the crash by ensuring that refcounts in channels are handled properly.