Construct an Digitizer viewer, given a filename.
// GUI SETUP
cp = this;
cp.setLayout(new GridLayout(1, 0, 10, 10));
iv = new ImageView("foo");
cp.add(iv);
JList list = new JList();
cp.add(list);
Grapher gr = new Grapher();
cp.add(gr);
// EVENT SETUP
MouseClicker mickey = new MouseClicker();
iv.addMouseListener(mickey);
iv.addMouseMotionListener(mickey);