support key with query

我的key带有参数：```?imageView2/1/w/64/h/64```，签名得到的url: http://temp-cloud3edu-com.qiniudn.com/yTWNJ8G1PT%2F%C3%A7%C2%8B%C2%97.jpg%3FimageView2%2F1%2Fw%2F64%2Fh%2F64%3FimageView2%2F1%2Fw%2F64%2Fh%2F64?e=1408784355&token=_NXt69baB3oKUcLaHfgV5Li-W_LQ-lhJPhavHIc_:DhoYgHasg_CqzVenKDl0PvZ19e8=
返回结果为```{"error":"Not Found"}```

解决方法：
```
function makeBaseUrl(domain, key) {
key = new Buffer(key);
return 'http://' + domain + '/' + querystring.escape(key);
}
```
这里querystring.escape会把query转掉，整个key就错了，应该提供个参数，可以传query
```
function makeBaseUrl(domain, key, query) {
key = new Buffer(key);
return 'http://' + domain + '/' + querystring.escape(key) + query; // query like '?imageView2/1/w/64/h/64'
}
```