Created by Jerry Wang, last modified on Jul 27, 2015
修改了lead的数据之后点击save button，首先从后台重新读取一次lead的数据：
SAP OData 后台ETAG校验逻辑Created by Jerry Wang, last modified on Jul 27, 2015 
SAP OData 后台ETAG校验逻辑Created by Jerry Wang, last modified on Jul 27, 2015 SAP OData 后台ETAG校验逻辑Created by Jerry Wang, last modified on Jul 27, 2015 SAP OData 后台ETAG校验逻辑Created by Jerry Wang, last modified on Jul 27, 2015 SAP OData 后台ETAG校验逻辑Created by Jerry Wang, last modified on Jul 27, 2015 
