建议NavTab 修改为control模式

[gallex]

Do you want to request a feature or report a bug (建议还是bug) ? 建议 What is the current behavior? (现有状况) 目前NavTab是非controle模式，无法在程序中控制当前标签。 What is the expected behavior? （应有状况） 修改为controle模式。内部也可以维护一个状态，但是根据是否传入activeIndex props，修改内部状态。和react的标准控件一样处理。 Which versions of React-weui, weui, and which OS and device are affected by this issue? (React-weui版本 weui版本 机型和系统)