记录紧急下载Bug修复，备份

Vue下载文件，采用的创建iframe的方式。因为文件格式有pdf。浏览器在iframe里打开。因iframe是隐藏的不显示。造成点击下载无反应的现象。。立马百度，采用download.js的方式下载。修改源码。注释掉 url = !strFileName && !strMimeType && payload,可以直接传url，注释掉 if(anchor.href.indexOf(url) !== -1)判断，因为路径有中文。在vue中引入。download(url)方式调用

function download(data, strFileName, strMimeType) {
    var self = window, // this script is only for browsers anyway...
            defaultMime = "application/octet-stream", // this default mime also triggers iframe downloads
            mimeType = strMimeType || defaultMime,
            payload = data,
            // url = !strFileName && !strMimeType && payload,
            url = payload,
            anchor = document.createElement("a"),
            toString = function(a){return String(a);},
            myBlob = (self.Blob || self.MozBlob || self.WebKitBlob || toString),
            fileName = strFileName || "download",
            blob,
            reader;
            myBlob= myBlob.call ? myBlob.bind(self) : Blob ;
      
        if(String(this)==="true"){ //reverse arguments, allowing download.bind(true, "text/xml", "export.xml") to act as a callback
            payload=[payload, mimeType];
            mimeType=payload[0];
            payload=payload[1];
        }


        if(url && url.length< 2048){ // if no filename and no mime, assume a url was passed as the only argument
            fileName = url.split("/").pop().split("?")[0];
            anchor.href = url; // assign href prop to temp anchor
            // if(anchor.href.indexOf(url) !== -1){ // if the browser determines that it's a potentially valid url path:
                var ajax=new XMLHttpRequest();
                ajax.open( "GET", url, true);
                ajax.responseType = 'blob';
                ajax.onload= function(e){ 
                  download(e.target.response, fileName, defaultMime);
                };
                setTimeout(function(){ ajax.send();}, 0); // allows setting custom ajax headers using the return:
                return ajax;
            // } // end if valid url?
        } // end if url?


        //go ahead and download dataURLs right away
        if(/^data\:[\w+\-]+\/[\w+\-]+[,;]/.test(payload)){
        
            if(payload.length > (1024*1024*1.999) && myBlob !== toString ){
                payload=dataUrlToBlob(payload);
                mimeType=payload.type || defaultMime;
            }else{          
                return navigator.msSaveBlob ?  // IE10 can't do a[download], only Blobs:
                    navigator.msSaveBlob(dataUrlToBlob(payload), fileName) :
                    saver(payload) ; // everyone else can save dataURLs un-processed
            }
            
        }//end if dataURL passed?

        blob = payload instanceof myBlob ?
            payload :
            new myBlob([payload], {type: mimeType}) ;


        function dataUrlToBlob(strUrl) {
            var parts= strUrl.split(/[:;,]/),
            type= parts[1],
            decoder= parts[2] == "base64" ? atob : decodeURIComponent,
            binData= decoder( parts.pop() ),
            mx= binData.length,
            i= 0,
            uiArr= new Uint8Array(mx);

            for(i;i