FIRST

Three options:
Add a getFrame method
Add delegate methods to add listeners to the frame
Make constructor take a wizard event listener as a parameter to constructor, and add it as a listener automatically.

If we do getFrame() then we can also access the wizard data object at that point. This complicates the interface to RunWizard.

I'm leaning toward the constructor method, along with an explicit delegated getWizardData method.