Benchmark (with docs) for Socks5 proxy

![image](https://cloud.githubusercontent.com/assets/4954150/4410799/e1c487a0-44e8-11e4-83ba-8af8ff0985fc.png)

Currently detects the data channel limit bug.
So, I think it'd be better if we could keep the third party stuff inside `build/typescript-src/third_party/`.

I spent some time thinking while trying to make conditional compilation happen. The best/simplest I could manage was create a symlink to each direct sub-directory of `third_party/`:
https://github.com/uProxy/uproxy-lib/pull/72/files#diff-a35864fcc4749a3b904641b4be9feacfR93

Here, I guess we'd "merge" `uproxy-lib`'s and `uproxy-networking`'s `third_party/` directories.