Move all #ifdef HAVE_HEADER_H #include <header.h> to have.h,

this allows for simplification of configure.in.

system.h

@@ -23,116 +23,14 @@
 
 #include "config.h"
 
-/* Include standard headers */
+#include "have.h"
 
-#include <stdio.h>
-#include <stdlib.h>
-#include <stdarg.h>
-#include <string.h>
-#include <ctype.h>
-#include <signal.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <unistd.h>
-
-#ifdef HAVE_STDBOOL_H
-#include <stdbool.h>
-#else
+#ifndef HAVE_STDBOOL_H
 typedef int bool;
 #define true 1
 #define false 0
 #endif
 
-#ifdef HAVE_TERMIOS_H
-#include <termios.h>
-#endif
-
-#ifdef HAVE_INTTYPES_H
-#include <inttypes.h>
-#endif
-
-/* Include system specific headers */
-
-#ifdef HAVE_SYSLOG_H
-#include <syslog.h>
-#endif
-
-#ifdef HAVE_SYS_TIME_H
-#include <sys/time.h>
-#endif
-
-#ifdef HAVE_SYS_TYPES_H
-#include <sys/types.h>
-#endif
-
-#ifdef HAVE_SYS_STAT_H
-#include <sys/stat.h>
-#endif
-
-#ifdef HAVE_SYS_FILE_H
-#include <sys/file.h>
-#endif
-
-#ifdef HAVE_SYS_WAIT_H
-#include <sys/wait.h>
-#endif
-
-#ifdef HAVE_SYS_IOCTL_H
-#include <sys/ioctl.h>
-#endif
-
-#ifdef HAVE_SYS_PARAM_H
-#include <sys/param.h>
-#endif
-
-/* SunOS really wants sys/socket.h BEFORE net/if.h,
-   and FreeBSD wants these lines below the rest. */
-
-#ifdef HAVE_NETDB_H
-#include <netdb.h>
-#endif
-
-#ifdef HAVE_SYS_SOCKET_H
-#include <sys/socket.h>
-#endif
-
-#ifdef HAVE_NET_IF_H
-#include <net/if.h>
-#endif
-
-#ifdef HAVE_NETINET_IN_SYSTM_H
-#include <netinet/in_systm.h>
-#endif
-
-#ifdef HAVE_NETINET_IN_H
-#include <netinet/in.h>
-#endif
-
-#ifdef HAVE_ARPA_INET_H
-#include <arpa/inet.h>
-#endif
-
-#ifdef HAVE_NETINET_IP_H
-#include <netinet/ip.h>
-#endif
-
-#ifdef HAVE_NETINET_TCP_H
-#include <netinet/tcp.h>
-#endif
-
-#ifdef HAVE_NETINET_IN6_H
-#include <netinet/in6.h>
-#endif
-
-#ifdef HAVE_NETINET_IP6_H
-#include <netinet/ip6.h>
-#endif
-
-#ifdef HAVE_MINGW
-#include <windows.h>
-#include <winsock2.h>
-#endif
-
 /* Include localisation support */
 
 #include "gettext.h"