fix a lot of Tkinter imports
diff --git a/Demo/tkinter/matt/canvas-moving-w-mouse.py b/Demo/tkinter/matt/canvas-moving-w-mouse.py
index 81785d8..21d724f 100644
--- a/Demo/tkinter/matt/canvas-moving-w-mouse.py
+++ b/Demo/tkinter/matt/canvas-moving-w-mouse.py
@@ -1,4 +1,4 @@
-from Tkinter import *
+from tkinter import *
 
 # this file demonstrates the movement of a single canvas item under mouse control