qrcode 生成PNG文件二维码

参数:

   url=要生成二维码的网址

   size=返回的图片宽高

   level=容错等级[l=7%,m=15%,q=25%,h=30%]

返回: img=BASE64图片，code=为空时正常，不为空是错误信息

例子:

   <!--{ffwbms_func qrcode,aa,"url=http://www.ffwish.com|size=100|level=q"}-->

   <!--{ffwbms_see $aa}-->

   <img src="data:image/png;base64,<!--{$aa['img']}-->" />

返回：

   {

 "code": "",

 "img": "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"

}