对于无扩展名文件，会尝试按照image处理

[zensh]

比如上传 README：

    Resource interpreted as Image but transferred with MIME type text/plain: "blob:http%3A//project.ci/f235535a-3217-4211-9f83-99b0f2b091fb". webuploader.html5only.js:5339
    Html5Runtime.register.loadFromBlob webuploader.html5only.js:5339
    Html5Runtime.me.exec webuploader.html5only.js:4313
    RuntimeClient.exec webuploader.html5only.js:1134
    (anonymous function) webuploader.html5only.js:2007
    fire jquery.js:2913
    self.fireWith jquery.js:3025
    deferred.(anonymous function) jquery.js:3114
    (anonymous function) jquery.js:3069
    fire jquery.js:2913
    self.add jquery.js:2959
    (anonymous function) jquery.js:3068
    jQuery.extend.each jquery.js:590
    (anonymous function) jquery.js:3064
    jQuery.extend.Deferred jquery.js:3125
    promise.then jquery.js:3063
    RuntimeClient.connectRuntime webuploader.html5only.js:1098
    Base.inherits.loadFromBlob webuploader.html5only.js:2005
    (anonymous function) webuploader.html5only.js:2252
    tick webuploader.html5only.js:2057

实际上无扩展名的文件通常是text文件

[2betop]

代码逻辑有误，感谢反馈，已修复