(cherry picked from commit 604e7b99)
Co-authored-by: Tal Einat <taleinat+github@gmail.com>

Update and augment description of the configuration system.

Make the default key set depend on the platform.
Add tests for changes to the config module.

address the compatibility problem introduced by the addition of IDLE Dark.
Consistently use the revised idleConf.CurrentTheme everywhere in idlelib.

editor font.  This should not affect current customized font selections.
Patch by Mark Roseman.

configuration dialog.  Patch by Tal Einat.

Default remains cyclic.  Python Patch 914546 Noam Raphael.

M IdleHistory.py
M NEWS.txt
M config-main.def

backported to 23-maint

abnormal exit situations cleanly, especially stuck user threads.  Future
plan is to intercept the user's atexit functions and run them under
IDLE's control.

is not to do that.  VPython and student environment support.

M PyShell.py
M config-main.def
M run.py

   The default font is not highlighted in the Options dialog when
   IDLEfork is first installed.

2. Reduce default font to 10 pt and increase default window height to give
   a better initial impression on Windows.

M config-main.def
M configDialog.py

SF 661318

Adds autosave capability to IDLE and IDLE configuration dialog.

User can Run/F5 without explicit save dialog.

The default is to require the user to confirm the save.

M ScriptBinding.py
M config-main.def
M configDialog.py

 Modified Files:
 	config-extensions.def config-highlight.def config-keys.def
 	config-main.def

M IOBinding.py
M config-main.def
M configDialog.py

M EditorWindow.py
M NEWS.txt
M config-main.def
M configDialog.py
M configHandler.py
M configHelpSourceEdit.py
M configSectionNameDialog.py

- Change default: IDLE now starts with Python Shell.

- Removed the File Path from the Additional Help Sources scrolled list.

- Add capability to access Additional Help Sources on the web if the
  Help File Path begins with //http or www.  (Otherwise local path is
  validated, as before.)

- Additional Help Sources were not being posted on the Help menu in the
  order entered.  Implement sorting the list by [HelpFiles] 'option'
  number.

- Add Browse button to New Help Source dialog.  Arrange to start in
  Python/Doc if platform is Windows, otherwise start in current directory.

- Put the Additional Help Sources directly on the Help menu instead of in
  an Extra Help cascade menu.  Rearrange the Help menu so the Additional
  Help Sources come last.  Update help.txt appropriately.

- Fix Tk root pop-ups in configSectionNameDialog.py  and configDialog.py

slightly tweaked and modified for the idlefork config system

user defined help items

because of the way the tk text widget handles
tabs they must remain a fixed size in idle

beginning of configuration saving

further devel of highlight handling

plus misc fixes cleanups for new config system