WebSocket Client

[dkoontz]

Introduces a new WebSocketClient module for connecting to WebSocket servers, and adds configurable backpressure to both the client and server sides of the WebSocket API.

Backpressure (client + server)

• Both WebSocketClient.connect and WebSocketServer.createServer now take an options : Array Option field, currently supporting ReadBufferCapacity Int (default 16).
• src/Gren/Kernel/WebSocketServer.js — the per-connection ReadableStream now uses a CountQueuingStrategy with the configured highWaterMark; when the buffer fills, the underlying socket is pause()d, and the stream's pull callback resume()s it once the consumer drains. Note: this is a breaking API change to createServer (added required options field).