adds a data item to the list
| obj | object | the item object | 
| index | number | optional, the item's position (zero-based numbering) | 
var myList = new dhtmlXList({
    container:"data_container",
    type:{
        template:"Package"
    }
});
myList.add({
    id:15,
    Package:"test one",
    Version:"0.1",
    Maintainer:"dhtmlx" 
}, 0)
Note: