bpo-29446: IDLE -- add explicit imports (GH-14919) (GH-14920)

Stop depending on tkinter import *.
(cherry picked from commit c6fd6c83b70df76421d05a7628367e64a2f83589)

Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>
diff --git a/Lib/idlelib/editor.py b/Lib/idlelib/editor.py
index 497ee12..35027da 100644
--- a/Lib/idlelib/editor.py
+++ b/Lib/idlelib/editor.py
@@ -2,7 +2,9 @@
 import importlib.util
 import os
 import platform
+import re
 import string
+import sys
 import tokenize
 import traceback
 import webbrowser