This module provides a framework to produce sprite animations using ASCII art.
Each ASCII 'sprite' is given one or more frames, and placed into the animation
as an 'animation object'. An animation object can have a callback routine that
controls the position and frame of the object.
If the constructor is passed no arguments, it assumes that it is running full
screen, and behaves accordingly. Alternatively, it can accept a curses window
(created with the Curses new win call) as an argument, and will draw into that
window.
