rewrite ControlBlock.Open to only open passive connections; now use Send for active connections

tcp/handler_test.go

@@ -0,0 +1,20 @@
+package tcp
+
+import (
+	"math/rand"
+	"testing"
+)
+
+func TestHandler(t *testing.T) {
+
+}
+
+func setupClientServer(rng *rand.Rand) (client, server Handler) {
+
+	// err := server.Open(StateListen, uint16(rng.Uint32()), 0, 0)
+	// if err != nil {
+	// 	panic(err)
+	// }
+	// err = client.Open(State)
+	return client, server
+}