zoomLock下拖拽转移，提高用户体验
radar升级
文档、图片大小优化、雷达图例子更新
polar的legend判断逻辑错误
雷达图优化
1.2.0 release
Merge https://github.com/ecomfe/echarts/commit/fadd309b34384bf643ab0c65bcc50c45201686df