CSC323 2010S, Class 14: tkinter: Simple GUIs in Python

Overview:
* TkInter: A simple GUI toolkit.
* TkInter lab.

Admin:
* Don't forget to get your UML done for Tuesday's class.
* For Tuesday, Read Section 1 of Extreme Programming Explained.
* For Tuesday, Read BC 29.
* Respond to both readings.

Lab:

* Problem the first:  Create a window with a button that you can drag around
  the window.  (That is, you click on the button and can then drag it 
  anywhere.)  Then, make your code work with multiple buttons.  
  + Hint 1: You probably want to use the <code>place</code> layout
    manager.
  + Hint 2: Think about what event(s) to bind.
  + Hint 3: You may find it useful to print messages in the procedure
    that responds to messages.
  + Hint 4: You'll probably want to create a class to represent these
    draggable buttons.
* Problem the second: Permit the user to move one of the buttons using the
  arrow keys (or the legendary hjkl keys).
* Problem the third: Make a ten-by-ten grid of buttons and provide a method
  that, given a column, row, and color, sets the button at that position
  to the color.
* Problem the last: Create a simple non-working GUI for iSimGrinLife.  
  You should have the menu items that you expect to be in the GUI.