修复dropdown初始赋值
Merge pull request #109 from RubyLouvre/master

Merge pull request #368 from ilife5/master
update dropdown
merge
Merge pull request #110 from RubyLouvre/master

merge from RubyLouvre/onionui
Merge pull request #111 from RubyLouvre/master

merge from RubyLouvre/onionui
Merge pull request #376 from ilife5/master

dropdown增加异步渲染以及联动的例子