早前画了touch事件派发草图，重新整理了下
Touch Event: Down
Down事件，无论
clickable与否都会各层级传递
Touch Event: Move
| Hierarchy | clickable/longClickable |
|---|---|
| Parent | false |
| Child | false |
| Hierarchy | clickable/longClickable |
|---|---|
| Parent | false/true |
| Child | true |
| Hierarchy | clickable/longClickable |
|---|---|
| Parent | true |
| Child | false |
Touch Event: Up
| Hierarchy | clickable/longClickable |
|---|---|
| Parent | false |
| Child | false |
| Hierarchy | clickable/longClickable |
|---|---|
| Parent | true/false |
| Child | true |
| Hierarchy | clickable/longClickable |
|---|---|
| Parent | true |
| Child | false |
