function handleMouseEnter(e) {
      var cell = _grid.getCellFromEvent(e);
      if (cell) {
        var $node = $(_grid.getCellNode(cell.row, cell.cell));
        var text;
        if ($node.innerWidth() < $node[0].scrollWidth) {
          text = $.trim($node.text());
          if (options.maxToolTipLength && text.length > options.maxToolTipLength) {
            text = text.substr(0, options.maxToolTipLength - 3) + "...";
          }
        } else {
          text = "";
        }
        $node.attr("title", text);
      }
    }
Handle mouse entering grid cell to add/remove tooltip.
@param {jQuery.Event} e - The event