demo编辑支持
demo 基本操作完成
Draggable 拖放后释放事件
贝塞尔文档更新
修改调用moveVertex的接口为moveTo
控制点对称联动交由用户选择
Merge branch 'dev' of github.com:HanCong03/kitygraph into dev
Merge remote-tracking branch 'jm/dev' into dev
demo 合并和调整
Viewport Support
Coordinate fix for viewport
shapecontainer events
getPaperPromise 允许在图形挂载到 paper 后回调
extendClass 返回被拓展的类
Viewport and Draggable