1.0.1

1. add border radius support for Layer
2. add didFinishBinding callback for widget
3. fix draw order of virtual layers & widgets
4. fix size and reuse issues of NText widget
5. fix a mem leak
6. fix a crash of unsafe delegate
7. fix hitTest order
8. make rate of VVSystemKey can be modified
9. fix support of textStyle
10. fix type error while call registerWidget
11. remove some dirty comments