fix the tap bug: when the list page is scrolling, the first tap is expected to stop scrolling rather than trigger tap events on IOS

To the topic, it's really a difficult question. But I'm so glad that I fix it.
The question is, when you scroll fast the list and leave your finger, the first tap is to stop scrolling rather than trigger the tap events before the scroll element is stopped on IOS platform.

My code is tested by my group and has already using in our project. The following is brief introduction to my thought.

1. check which dom will be scrolling
2. check if continue scrolling when leave finger
3. continue scrolling, set interval to identity scrolling stopped, if stopped, the first tap will trigger tap events, else do nothing