new file:   CanvasGroup.js
	modified:   CanvasLayer.js
	modified:   CanvasRenderer.js
	modified:   Containable.js
	modified:   Container.js
	new file:   GraphicContainer.js
	new file:   GraphicGroup.js
	modified:   GraphicLayer.js
	new file:   GraphicShape.js
	modified:   Graphics2D.js
	modified:   shape/Arc.js
	modified:   shape/Circle.js
	modified:   shape/Ellipse.js
	modified:   shape/Image.js
	modified:   shape/Line.js
	modified:   shape/Polygon.js
	modified:   shape/Polyline.js
	modified:   shape/Rect.js
	modified:   shape/Text.js
	modified:   ../util/Observable.js