2. 过滤多余的 pickerSelectedVal

1. 列数增加: 增加的列对应的 scroll 未实例化无法滚动
2. 列数减少: pickerSelectedVal 保留了变化前选中的值

* checkbox&radio: no item background color, but group has background color and moved state classes to root elements

* radio&checkbox: support native style & muti background colors

* update(example): checkbox & radio

* update(test): checkbox & radio tests

* input, select and textarea css style

* update(example): component order

* rate support justify

* support password eye, issue #107

* update input, select and textarea line-height

* update(test): input add pwdEye

* update(test): rate test

* radio format

* nativeStyle to hollowStyle

* update checkbox example

* update(doc): checkbox and radio doc

* input pwdEye support string value

* rate demo & doc

* rate demo & doc

* update(doc): select add picker-show and picker-hide events

* update input doc & demo

* password eye

* upgrade copy-webpack-plugin

* remove scroll useless prop

* input demo

* input demo