图片上传处理类，简单方用，静态方法，只须要把表单名字，保存路径调用就可以返回保存缩略图后的结果。可选缩放方式丰富。-Image upload processing class, the simple side with a static method, simply take the form name, the call of the save path can return to save the results after the thumbnail. Optional zoom way