Handle subnormal weights for choices()

Import pyshell first in htest to call SetProcessDpiAwareness on Windows
before tkinter.Tk() is called for the htest. Apparently, 'root.destroy()'
undoes a previous 'root = Tk()'. Since IDLE unittests always destroy roots,
a unittest before an htest does not require anything more to work right.
Since part of the purpose of human-viewed tests is to determine that
widgets look right, it is important that they look the same for testing
as when running IDLE.

it's better to refer to PEP with `pep` role in reStructuredText. It also links to the PEP page.

Fix bug in `Lib/test/libregrtest/runtest.py` that makes running tests an extra time than the specified number of runs.

Add check for invalid --huntrleaks/-R parameters.

These should have been included in PR 7836.

This reverts commit 8fbbdf0c.

Adds references to info about file modes, `time.strftime()`, string formatting
syntaxes, and logging levels.

This avoids a failure in at least one case when running only a single
test method rather than all tests in the module.

The issue came up when testing the following on Windows 10 Pro 64-bit:
HighPageTest.test_highlight_target_text_mouse

Directly executed pyc files were being kept open longer than necessary.

(cherry picked from commit c45cb479074b5d25f0d382d3109f527520a9f03c)
Co-authored-by: Andrés Delfino <adelfino@gmail.com>

In configdialog, the custom tabbedpages widget was replaced
by ttk.notebook several months ago.

bz2, lzma: When Decompressor.__init__() is called twice, free the old
lock to not leak memory.

The statement is true for Windows (and macOS) also.

* Add support.MS_WINDOWS: True if Python is running on Microsoft Windows.
* Add support.MACOS: True if Python is running on Apple macOS.
* Replace support.is_android with support.ANDROID
* Replace support.is_jython with support.JYTHON
* Cleanup code to initialize unix_shell

Calling Py_Initialize() twice does nothing, instead of failing with a
fatal error: restore the Python 3.6 behaviour.

Increases coverage by 44%.

Add missing warning filter to test_exec_filename().

Increase the timeout from 1 min to 5 min.

Replace also time.time() with time.monotonic() for timeouts.

Every other menudef key is the lowercase version of the
corresponding main menu entry (in this case, 'Window').

Match Window on the main menu and remove last plural module name.
Change imports, test, and attribute references to match new name.

The revised file compiles, runs, and tests OK. idle_test/README.txt
explains how to use it to create new IDLE test files.

Initial What's New in Python 3.8 entry for `PYTHONPYCACHEPREFIX`.

Only make sure that the result is in unittest.signals._results, don't
check the full content of unittest.signals._results.

support._run_suite() uses TextTestRunner in verbose mode, but
TextTestRunner.run() calls registerResult(result) which made the test
fail with "odd object in result set".

Call also removeResult() to restore unittest.signals._results to
avoid test side effect.

Fix-up class name duplication in PR #7807. Combined effect is that
module calltips and its class CallTips are now calltip and Calltip.
In module calltip_w class CallTip is now CalltipWindow.

Signed-off-by: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>