Fix clearing of animation effects and prioritise animations by start time
Fix clearing of animation effects and prioritise animations by start time

birtles/web-animations-js,beni55/web-animations-js-legacy,web-animations/web-animations-js-legacy,beni55/web-animations-js-legacy,beni55/web-animations-js-legacy,web-animations/web-animations-js-legacy,dstockwell/web-animations-js,beni55/web-animations-js-legacy,dstockwell/web-animations-js,birtles/web-animations-js,shans/web-anim-js,web-animations/web-animations-js-legacy,birtles/web-animations-js