The original module-level class and method browser became a module
browser, with the addition of module-level functions, years ago.
Nested classes and functions were added yesterday. For back-
compatibility, the virtual event <<open-class-browser>>, which
appears on the Keys tab of the Settings dialog, is not changed.
Patch by Cheryl Sabella.
This follows the previous patch that changed idlelib file names.
Class names that matched old module names are not changed.
Change idlelib imports in turtledemo.__main__.
Exception: config-extensions.def. Previously, extension section
names, file names, and class names had to match. Changing section
names would create cross-version conflicts in config-extensions.cfg
(user customizations). Instead map old names to new file names
at point of import in editor.EditorWindow.load_extension.
Patch extensively tested with test_idle, idle_test.htest.py, a custom
import-all test, running IDLE in a console to catch messages,
and testing each menu item. Based on a patch by Al Sweigart.
Terry Jan Reedy
Cheryl Sabella