fixup windows and older linux builds

include/Makefile.am

@@ -31,6 +31,7 @@ noinst_HEADERS += compat/sys/ioctl.h
 noinst_HEADERS += compat/sys/mman.h
 noinst_HEADERS += compat/sys/param.h
 noinst_HEADERS += compat/sys/select.h
+noinst_HEADERS += compat/sys/socket.h
 noinst_HEADERS += compat/sys/stat.h
 noinst_HEADERS += compat/sys/time.h
 noinst_HEADERS += compat/sys/types.h

include/compat/sys/socket.h

@@ -0,0 +1,10 @@
+/*
+ * Public domain
+ * sys/socket.h compatibility shim
+ */
+
+#ifndef _WIN32
+#include_next <sys/socket.h>
+#else
+#include <win32netcompat.h>
+#endif

patches/netcat.c.patch

@@ -1,5 +1,5 @@
 --- apps/nc/netcat.c.orig	Sun Sep 13 08:12:39 2015
-+++ apps/nc/netcat.c	Sun Sep 13 16:39:51 2015
++++ apps/nc/netcat.c	Sun Sep 13 18:56:27 2015
 @@ -98,9 +98,13 @@
  int	Dflag;					/* sodebug */
  int	Iflag;					/* TCP receive buffer size */
@@ -83,7 +83,7 @@
  			memset(&ahints, 0, sizeof(struct addrinfo));
  			ahints.ai_family = res0->ai_family;
  			ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM;
-@@ -887,9 +902,11 @@
+@@ -887,13 +902,17 @@
  		    res0->ai_protocol)) < 0)
  			continue;
  
@@ -93,9 +93,15 @@
  			err(1, "setsockopt SO_RTABLE");
 +#endif
  
++#ifdef SO_REUSEPORT
  		ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x));
  		if (ret == -1)
-@@ -1337,11 +1354,13 @@
+ 			err(1, NULL);
++#endif
+ 
+ 		set_common_sockopts(s, res0->ai_family);
+ 
+@@ -1337,11 +1356,13 @@
  {
  	int x = 1;
  
@@ -109,7 +115,7 @@
  	if (Dflag) {
  		if (setsockopt(s, SOL_SOCKET, SO_DEBUG,
  			&x, sizeof(x)) == -1)
-@@ -1516,15 +1535,19 @@
+@@ -1516,15 +1537,19 @@
  	\t-P proxyuser\tUsername for proxy authentication\n\
  	\t-p port\t	Specify local port for remote connects\n\
  	\t-R CAfile	CA bundle\n\