workaround redefinition of struct timeval on NetBSD

[Yorick Hardy]

Test programs which include winsock.h and time.h cause a redefinition
of struct timeval on NetBSD. This is because time.h includes sys/time.h.
A workaround is provided below.

-- 
Yorick Hardy

--- include/winsock.h	Sat May 17 10:09:32 2003
+++ include/winsock.h	Sat May 24 15:32:29 2003
@@ -65,6 +65,7 @@
 #  define timeval unix_timeval
 #  define select unix_select
 #  include <sys/types.h>
+#  include <sys/time.h>
 #  include <stdlib.h>
 #  undef fd_set
 #  undef timeval