fix bug in _super. in IE, the second argument to Function.apply can't be undefined
fix bug in _super. in IE, the second argument to Function.apply can't be undefined

hewtest/chorus,lukepolo/chorus,atul-alpine/chorus,jamesblunt/chorus,atul-alpine/chorus,mpushpav/chorus,atul-alpine/chorus,hewtest/chorus,hewtest/chorus,hewtest/chorus,jamesblunt/chorus,lukepolo/chorus,prakash-alpine/chorus,prakash-alpine/chorus,jamesblunt/chorus,lukepolo/chorus,jamesblunt/chorus,atul-alpine/chorus,mpushpav/chorus,mpushpav/chorus,hewtest/chorus,hewtest/chorus,hewtest/chorus,lukepolo/chorus,atul-alpine/chorus,jamesblunt/chorus,jamesblunt/chorus,hewtest/chorus,prakash-alpine/chorus,atul-alpine/chorus,mpushpav/chorus,prakash-alpine/chorus,mpushpav/chorus,lukepolo/chorus,mpushpav/chorus,jamesblunt/chorus,lukepolo/chorus,mpushpav/chorus,atul-alpine/chorus,prakash-alpine/chorus,lukepolo/chorus