NewWebsocketListener to handle websocket connections ln: tcp listener for websocket connections.

closeFn will be only called once.

ConnectedUDPConn is a wrapper for net.UDPConn which converts WriteTo syscalls to Write syscalls that are 4 times faster on some OS'es.

ContextConn is the connection with context.

InternalListener is a listener that can be used to accept connections from other goroutines.