function refreshInstance (instanceId, data) {
  var instance = instances[instanceId];
  if (!instance || !(instance.app instanceof instance.Vue)) {
    return new Error(("refreshInstance: instance " + instanceId + " not found!"))
  }
  for (var key in data) {
    instance.Vue.set(instance.app, key, data[key]);
  }
  // Finally `refreshFinish` signal needed.
  instance.document.taskCenter.send('dom', { action: 'refreshFinish' }, []);
}
Refresh an instance with id and new top-level component data.
It will use `Vue.set` on all keys of the new data. So it's better
define all possible meaningful keys when instance created.
@param {string} instanceId
@param {object} data