Add more net compatibility

Required for net/http.

tcpsock.go

@@ -0,0 +1,11 @@
+package net
+
+// TCPConn is an implementation of the Conn interface for TCP network
+// connections.
+type TCPConn struct {
+	conn
+}
+
+func (c *TCPConn) CloseWrite() error {
+	return &OpError{"close", "", nil, nil, ErrNotImplemented}
+}