Resolve MSVC10 warnings about error macro redefinitions.

src/xpdev/sockwrap.h

@@ -98,13 +98,27 @@ typedef struct {
 #undef  EWOULDBLOCK
 #define EWOULDBLOCK		(WSAEWOULDBLOCK-WSABASEERR)
 
+#ifndef EPROTOTYPE
 #define EPROTOTYPE		(WSAEPROTOTYPE-WSABASEERR)
+#endif
+#ifndef ENOPROTOOPT
 #define ENOPROTOOPT		(WSAENOPROTOOPT-WSABASEERR)
+#endif
+#ifndef EPROTONOSUPPORT
 #define EPROTONOSUPPORT	(WSAEPROTONOSUPPORT-WSABASEERR)
+#endif
+#ifndef ESOCKTNOSUPPORT
 #define ESOCKTNOSUPPORT	(WSAESOCKTNOSUPPORT-WSABASEERR)
+#endif
+#ifndef EOPNOTSUPP
 #define EOPNOTSUPP		(WSAEOPNOTSUPP-WSABASEERR)
+#endif
+#ifndef EPFNOSUPPORT
 #define EPFNOSUPPORT	(WSAEPFNOSUPPORT-WSABASEERR)
+#endif
+#ifndef EAFNOSUPPORT
 #define EAFNOSUPPORT	(WSAEAFNOSUPPORT-WSABASEERR)
+#endif
 
 #undef  EADDRINUSE
 #define EADDRINUSE		(WSAEADDRINUSE-WSABASEERR)