SubprotocolHandler middleware

[sirn-se]

Subprotocol negotiation middleware.

Can be used on both Client and Server to help them negotiate a subprotocol to use, by evaluating lists of supported protocols provided. It does NOT implement any subprotocol, but act as a helper for negotiation.

Optionally there's a require parameter. If set, Client will throw an exception. Server will decline Handshake.

Scheduled for v2.2.

[coveralls]

coverage: 100.0%. remained the same
when pulling ee5b1d8 on subprotocol-middleware
into 129db7c on v2.2-main.

[ChristianVermeulen]

This looks a-ok to me! If we could just turn those echo-lines into $logger->debug() or remove then that would be perfect :-) (i don't have write access to update it)