Use something smarter than `Show/Read` for the websockets protocol

I just tried to use `Data.Serialize` with generic deriving, but am stuck. While `Network.WebSockets` (the server side) has no problems sending binary data (as a `ByteString`) over the wire, the corresponding support in ghcjs, at , seems to be shaky. I might get a `Blob` out, but I do not see how to get a `ByteString` out.

I think I was at this point before, so I record this here.

Either I need to figure out how to work with `ByteString` in GHCJS, or use a different serialization library which targets `Data.Text`.

首先阅读 Network.WebSockets 的服务器端二进制数据路径和 ghcjs-base's JavaScript/Web/MessageEvent.hs，然后比较 issue 中提到的 ByteString 和 Data.Text 选项。当 WebSocket 协议不再依赖 Show/Read，且所选表示形式能够在服务器和 GHCJS 客户端上正常工作时，即视为完成。

由索引模型根据 Issue 内容生成。