node上传模块busboy

##基本用法

var Busboy = require('busboy');
exports.upload = function(req, res){
  busboy.on('file', function (fieldname, file, filename, encoding, mimetype) {
        var saveTo = path.join(__dirname, '../public/uploads', path.basename(filename));
        photo = saveTo;
        file.pipe(fs.createWriteStream(saveTo));
    });
	 busboy.on('finish', function () {
		 // 业务逻辑代码
            res.redirect('/');
        });
    });
    return req.pipe(busboy);
}   
\n```
##表单有其他非文件字段
```js\n
 busboy.on('field', function (fieldname, val) {
        if (fieldname == 'school')
            var school = validator.trim(inspect(val));
        if (fieldname == 'hobby')
            var hobby = validator.trim(inspect(val));
    });
	\n```