table view 中左滑出现编辑、删除等自定义按钮

1.首先，table view 中左滑能够出现编辑、删除等自定义按钮
2.其次，点击编辑能进入编辑界面
3.最后，点击删除能够删除数据
4.题外话，可以自定义更多功能的按钮

    override func tableView(tableView: UITableView, editActionsForRowAtIndexPath indexPath: NSIndexPath) -> [UITableViewRowAction]? {
        
        let delete = UITableViewRowAction(style: UITableViewRowActionStyle.Normal, title: "删除") { (action, index) in
            self.items.removeAtIndex(indexPath.row)      
            let indexPaths = [indexPath]
            tableView.deleteRowsAtIndexPaths(indexPaths, withRowAnimation: .Automatic)
        }
       delete.backgroundColor = UIColor.redColor()
        
        let more = UITableViewRowAction(style: UITableViewRowActionStyle.Normal, title: "编辑") { (action, index) in
            let editItemNavigationController = self.storyboard!.instantiateViewControllerWithIdentifier("EditItemNavigationController") as! UINavigationController
            let controller = editItemNavigationController.topViewController as! AddItemViewController
             controller.delegate = self
             controller.itemToEdit = self.items[indexPath.row]
            self.presentViewController(editItemNavigationController, animated: true, completion: nil)  
        }
        more.backgroundColor = UIColor.orangeColor()
        
        return [delete,more]
        
    }