I've added script with animation loop via setInterval.
I've added new html page to play with sprites, created new scripts and
distributed files to new directories.
Dunno... some changes.
Some small changes - the one to commonObject is quite crucial.
Changes. Don't forget to clear engine.js from garbage!!!
I've fixed inheritance bug between Sprite and Moving object. That way of
inheritance creation
MovingObject.prototype = new Sprite();
MovingObject.prototype.constructor = MovingObject;
doesn't work. Two objects will have one prototype, whicj is quite bad =).