Updated deps; React Socket notify client of shutdown
Separated core interfaces into many
Removed initial version support out of handshake negotiator
Moved message parser responsibility to each version
Removed __toString method from MessageInterface as to not confuse message from payload
Support for RFC control frames
Support message concatenation
[BCB] (temporary) WsConnection hard coded to RFC version
Handshake checks for \r\n\r\n anywhere, not just at end of string
Moving forward we're going to assume `mbstring.func_overload` is off.
For that reason we're not going to call `mb_` functions when checking byte level strings.
Separated handshake negotiation into its own class
`HandshakeNegotiator` deals with Request/Response classes
These changes are geared towards separate responsibility
Refs #29
