update docs vue version

* add transfer

* Transfer: add English doc

* Transfer: add tests

* update locale files

default-value sets a default value when picker opens

* i18n: update doc about vue-i18n@6.x

* i18n: fix typo

* 统一使用es6风格的方式引入vue包

* 修正回车换行符处理，以免每次npm run dev 时，index.js都会更改

* 更新编码

Tree: fix registerNode error when nodeKey is 0

* Add button style to checkbox

* Implement min/max for checkbox button group

* Fixing a display bug when chekbox is ':checked'

* Update docs to integrate example button+min/max option

* Register correctly checkbox-button
Last fixes after cherry pick and bad rebase...