Results 2 issues of BH4EHN

As I read the code, the redbird use the `http-proxy` internally, so I think listen to the `proxyReq` and `proxyRes` event of `http-proxy` should work. But is there a better...

Sometimes it takes long time to load server list. I think the server list isn't modified frequently, maybe we can cache it, or we can specify the server list XML...