Added Sound.isLoaded().
Added Sound.isLoaded().

longtaoge/playn,ruslansennov/playn2,playn/playn,rachelharvey/playn,rachelharvey/playn,thecocce/playn-1,tinkerstudent/playn,thecocce/playn-1,tinkerstudent/playn,playn/playn,ruslansennov/playn2,longtaoge/playn,playn/playn