cleanup
remove non-tls from client
add Conn.WriteMagic()
move const vars to conn.go
move KeyPath, CertPath to client.go
remove transport.SendMagic()
remove Upgrade from transpor
update comment
move url.Update() to UpdateRequest()
move util.go into Util struct
stream.Send() Recv() to private
add State to Stream
add Stream.NewStream()
add UNSET flag
add state change with sending request
add CXT to conn
fix context name
fix NextStreamId using context
add Conn.Streams map of streamid:stream