Describe onAjaxError, errorHandler (#318)
Describe onAjaxError, errorHandler (#318)

* Describe onAjaxError

* Fix formatting, describe errorHandler

* Update client-side-with-jquery.md

DevExpress/DevExtreme.AspNet.Data,DevExpress/DevExtreme.AspNet.Data,AlekseyMartynov/DevExtreme.AspNet.Data,DevExpress/DevExtreme.AspNet.Data,AlekseyMartynov/DevExtreme.AspNet.Data,AlekseyMartynov/DevExtreme.AspNet.Data,DevExpress/DevExtreme.AspNet.Data,AlekseyMartynov/DevExtreme.AspNet.Data