Delete socket.upgradeReq when it is no longer needed to reduce memory usage

[feross]

Each time a websocket sends a request, parseWebSocketRequest is called. On the first parse, save important data from socket.upgradeReq and delete it to reduce memory usage.

cc @lpinca @DiegoRBaquero

[lpinca]

Is parseWebSocketRequest() run multiple times for the same socket?

[feross]

@lpinca Yes, it's run each time we get a message on the socket.

[lpinca]

LGTM

[DiegoRBaquero]

LGTM

[lpinca]

Maybe you can null the property in Server.prototype.onWebSocketConnection() instead of parseWebSocketRequest(). It's arguably cleaner so you can avoid the additional if in parseWebSocketRequest().

[lpinca]

Anyway thank you for the invite @feross. I've accepted it but I know very little about this project and I doubt I can do any significant contribution :)