This function binds UNIX socket listener with specified path.
Any data received by this UNIX socket is sent out as a
WebSocket text frame. This allows a user to send data
on behalf of a running libwsclient program. Will add
some documentation for the entire library soon. Will go
into depth there.
Needed to have wsclient structure passed to callbacks for references
to sockfd or other API functions that need it. (libwsclient_close)
Also, respond to close frames correctly. Right now, we just wait
on server to close TCP connection without a timeout.