dwz 的td添加table(class="list")

return this.each(function(){
   var $this = $(this);
   var $trs = $this.find('tbody>tr');
   var $grid = $this.parent(); // table
   var nowrap = $this.hasClass("nowrap");
   //当table类名为list时，添加title提示语
   $trs.each(function(){
      $(this).children("td").mouseover(function () {
         $(this).attr("title", $(this).text());
      });
      $(this).children("td").css("white-space","nowrap");
   });