TODO

deprecate Body in favor of Prebody traits
deprecate Grid
deprecate GridWalker

DONE

@margin decorator
create @ratio({x, y})
remove @ratio.x().y()
remove @animation.show().hide
create @animation({show: {name, dur}, hide: {name, dur}})
@animation.show().hide() decorator
@ratio.x().y() decorator
@animation.show decorator
@animation.hide decorator
@ratio.x decorator
@ratio.y decorator