bpo-33855: More edits and new minimal tests for IDLE (GH-7761)


Part 2 of 3.  Continues PR GH-7689, changeset ee5ef30.
Edit and add tests for 18 modules, help_about to replace and run.
(cherry picked from commit ea3dc8029ab6a0f1ee6a8a72f1612dea74892e08)

Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>
diff --git a/Lib/idlelib/help_about.py b/Lib/idlelib/help_about.py
index 77b4b18..2a274a9 100644
--- a/Lib/idlelib/help_about.py
+++ b/Lib/idlelib/help_about.py
@@ -199,7 +199,8 @@
 
 
 if __name__ == '__main__':
-    import unittest
-    unittest.main('idlelib.idle_test.test_help_about', verbosity=2, exit=False)
+    from unittest import main
+    main('idlelib.idle_test.test_help_about', verbosity=2, exit=False)
+
     from idlelib.idle_test.htest import run
     run(AboutDialog)