Add '#include <netinet/tcp.h>'
"man tcp" on Solaris says that TCP_NODELAY is defined in
netinet/tcp.h, and the Open Groups Unix98 spec agrees
(http://www.opengroup.org/onlinepubs/009619199/ninettcp.htm).
diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index 9798dea..a6f4664 100644
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -163,6 +163,7 @@
#include <netdb.h>
#include <sys/socket.h>
#include <netinet/in.h>
+#include <netinet/tcp.h>
/* Headers needed for inet_ntoa() and inet_addr() */
#ifdef __BEOS__