message: fix(eventemitter): callback return
  the last callback's return value should be ignore, only respect those who returned true
diff: @@ -87,10 +87,11 @@ export default class EventEmitter {
  let [fn, context] = event
  if (fn) {
  ret = fn.apply(context, args)
  - if (ret === true) break
  + if (ret === true) {
  + return ret
  + }
  }
  }
  - return ret
  }
  registerType(names: string[]) {
  names.forEach((type: string) => {
  