HTTP and Listener improvements and bugfixes (#17)

* listener revamp

* improvements to conn lifetimes

x/xnet/xnet_concurrent_test.go

@@ -41,7 +41,8 @@ func TestTCPListener_ConcurrentEcho(t *testing.T) {
 	tcpPool, err := NewTCPPool(TCPPoolConfig{
 		PoolSize:           numClients,
 		QueueSize:          4,
-		BufferSize:         512,
+		TxBufSize:          512,
+		RxBufSize:          512,
 		EstablishedTimeout: 5 * time.Second,
 		ClosingTimeout:     5 * time.Second,
 	})
@@ -198,7 +199,7 @@ func echoServer(ctx context.Context, listener *tcp.Listener) {
 			continue
 		}
 
-		conn, err := listener.TryAccept()
+		conn, _, err := listener.TryAccept()
 		if err != nil || conn == nil {
 			continue
 		}