fix a lot of Tkinter imports
diff --git a/Demo/tkinter/guido/paint.py b/Demo/tkinter/guido/paint.py
index 7b2e814..65f2353 100644
--- a/Demo/tkinter/guido/paint.py
+++ b/Demo/tkinter/guido/paint.py
@@ -20,7 +20,7 @@
                                                 davem@magnet.com
 """
 
-from Tkinter import *
+from tkinter import *
 
 """paint.py: not exactly a paint program.. just a smooth line drawing demo."""