ajax上传文件，有进度条显示上传的百分比，性能不错，先上传到内存，在到服务端。

ajax上传文件，有进度条显示上传的百分比，性能不错，先上传到内存，在到服务端。-ajax upload files, has the progress bar shows the percentage of upload, performance good, first upload it to memory, in to the service client.