Install gnulib to make sure we can use argp in ltlfilt.

* lib/Makefile.am, lib/alloca.c, lib/alloca.in.h, lib/argp-ba.c,
lib/argp-eexst.c, lib/argp-fmtstream.c, lib/argp-fmtstream.h,
lib/argp-fs-xinl.c, lib/argp-help.c, lib/argp-namefrob.h,
lib/argp-parse.c, lib/argp-pin.c, lib/argp-pv.c, lib/argp-pvh.c,
lib/argp-xinl.c, lib/argp.h, lib/asnprintf.c, lib/basename-lgpl.c,
lib/dirname-lgpl.c, lib/dirname.h, lib/dosname.h, lib/errno.in.h,
lib/float+.h, lib/float.c, lib/float.in.h, lib/getopt.c,
lib/getopt.in.h, lib/getopt1.c, lib/getopt_int.h, lib/gettext.h,
lib/intprops.h, lib/itold.c, lib/malloc.c, lib/memchr.c,
lib/memchr.valgrind, lib/mempcpy.c, lib/printf-args.c,
lib/printf-args.h, lib/printf-parse.c, lib/printf-parse.h,
lib/rawmemchr.c, lib/rawmemchr.valgrind, lib/size_max.h,
lib/sleep.c, lib/stdalign.in.h, lib/stdbool.in.h, lib/stddef.in.h,
lib/stdint.in.h, lib/stdio.in.h, lib/stdlib.in.h, lib/strcasecmp.c,
lib/strchrnul.c, lib/strchrnul.valgrind, lib/strerror-override.c,
lib/strerror-override.h, lib/strerror.c, lib/string.in.h,
lib/strings.in.h, lib/stripslash.c, lib/strncasecmp.c,
lib/strndup.c, lib/strnlen.c, lib/sys_types.in.h, lib/sysexits.in.h,
lib/unistd.in.h, lib/vasnprintf.c, lib/vasnprintf.h, lib/verify.h,
lib/vsnprintf.c, lib/wchar.in.h, lib/xsize.h, m4/00gnulib.m4,
m4/alloca.m4, m4/argp.m4, m4/dirname.m4, m4/double-slash-root.m4,
m4/errno_h.m4, m4/exponentd.m4, m4/extensions.m4, m4/float_h.m4,
m4/getopt.m4, m4/gnulib-cache.m4, m4/gnulib-common.m4,
m4/gnulib-comp.m4, m4/gnulib-tool.m4, m4/include_next.m4,
m4/intmax_t.m4, m4/inttypes_h.m4, m4/longlong.m4, m4/malloc.m4,
m4/math_h.m4, m4/memchr.m4, m4/mempcpy.m4, m4/mmap-anon.m4,
m4/multiarch.m4, m4/nocrash.m4, m4/off_t.m4, m4/printf.m4,
m4/rawmemchr.m4, m4/size_max.m4, m4/sleep.m4, m4/ssize_t.m4,
m4/stdalign.m4, m4/stdbool.m4, m4/stddef_h.m4, m4/stdint.m4,
m4/stdint_h.m4, m4/stdio_h.m4, m4/stdlib_h.m4, m4/strcase.m4,
m4/strchrnul.m4, m4/strerror.m4, m4/string_h.m4, m4/strings_h.m4,
m4/strndup.m4, m4/strnlen.m4, m4/sys_socket_h.m4, m4/sys_types_h.m4,
m4/sysexits.m4, m4/unistd_h.m4, m4/vasnprintf.m4, m4/vsnprintf.m4,
m4/warn-on-use.m4, m4/wchar_h.m4, m4/wchar_t.m4, m4/wint_t.m4,
m4/xsize.m4, tools/snippet/_Noreturn.h, tools/snippet/arg-nonnull.h,
tools/snippet/c++defs.h, tools/snippet/warn-on-use.h: New files from
gnulib 1af55d85d9762a679b4302d5995f05ccd883e956.
* configure.ac, Makefile.am: Adjust to compile gnulib.
* src/bin/Makefile.am: Adjust to use gnulib.
* README: Mention lib/.

m4/errno_h.m4

@@ -0,0 +1,134 @@
+# errno_h.m4 serial 11
+dnl Copyright (C) 2004, 2006, 2008-2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN_ONCE([gl_HEADER_ERRNO_H],
+[
+  AC_REQUIRE([AC_PROG_CC])
+  AC_CACHE_CHECK([for complete errno.h], [gl_cv_header_errno_h_complete], [
+    AC_EGREP_CPP([booboo],[
+#include <errno.h>
+#if !defined ETXTBSY
+booboo
+#endif
+#if !defined ENOMSG
+booboo
+#endif
+#if !defined EIDRM
+booboo
+#endif
+#if !defined ENOLINK
+booboo
+#endif
+#if !defined EPROTO
+booboo
+#endif
+#if !defined EMULTIHOP
+booboo
+#endif
+#if !defined EBADMSG
+booboo
+#endif
+#if !defined EOVERFLOW
+booboo
+#endif
+#if !defined ENOTSUP
+booboo
+#endif
+#if !defined ENETRESET
+booboo
+#endif
+#if !defined ECONNABORTED
+booboo
+#endif
+#if !defined ESTALE
+booboo
+#endif
+#if !defined EDQUOT
+booboo
+#endif
+#if !defined ECANCELED
+booboo
+#endif
+#if !defined EOWNERDEAD
+booboo
+#endif
+#if !defined ENOTRECOVERABLE
+booboo
+#endif
+      ],
+      [gl_cv_header_errno_h_complete=no],
+      [gl_cv_header_errno_h_complete=yes])
+  ])
+  if test $gl_cv_header_errno_h_complete = yes; then
+    ERRNO_H=''
+  else
+    gl_NEXT_HEADERS([errno.h])
+    ERRNO_H='errno.h'
+  fi
+  AC_SUBST([ERRNO_H])
+  AM_CONDITIONAL([GL_GENERATE_ERRNO_H], [test -n "$ERRNO_H"])
+  gl_REPLACE_ERRNO_VALUE([EMULTIHOP])
+  gl_REPLACE_ERRNO_VALUE([ENOLINK])
+  gl_REPLACE_ERRNO_VALUE([EOVERFLOW])
+])
+
+# Assuming $1 = EOVERFLOW.
+# The EOVERFLOW errno value ought to be defined in <errno.h>, according to
+# POSIX.  But some systems (like OpenBSD 4.0 or AIX 3) don't define it, and
+# some systems (like OSF/1) define it when _XOPEN_SOURCE_EXTENDED is defined.
+# Check for the value of EOVERFLOW.
+# Set the variables EOVERFLOW_HIDDEN and EOVERFLOW_VALUE.
+AC_DEFUN([gl_REPLACE_ERRNO_VALUE],
+[
+  if test -n "$ERRNO_H"; then
+    AC_CACHE_CHECK([for ]$1[ value], [gl_cv_header_errno_h_]$1, [
+      AC_EGREP_CPP([yes],[
+#include <errno.h>
+#ifdef ]$1[
+yes
+#endif
+      ],
+      [gl_cv_header_errno_h_]$1[=yes],
+      [gl_cv_header_errno_h_]$1[=no])
+      if test $gl_cv_header_errno_h_]$1[ = no; then
+        AC_EGREP_CPP([yes],[
+#define _XOPEN_SOURCE_EXTENDED 1
+#include <errno.h>
+#ifdef ]$1[
+yes
+#endif
+          ], [gl_cv_header_errno_h_]$1[=hidden])
+        if test $gl_cv_header_errno_h_]$1[ = hidden; then
+          dnl The macro exists but is hidden.
+          dnl Define it to the same value.
+          AC_COMPUTE_INT([gl_cv_header_errno_h_]$1, $1, [
+#define _XOPEN_SOURCE_EXTENDED 1
+#include <errno.h>
+/* The following two lines are a workaround against an autoconf-2.52 bug.  */
+#include <stdio.h>
+#include <stdlib.h>
+])
+        fi
+      fi
+    ])
+    case $gl_cv_header_errno_h_]$1[ in
+      yes | no)
+        ]$1[_HIDDEN=0; ]$1[_VALUE=
+        ;;
+      *)
+        ]$1[_HIDDEN=1; ]$1[_VALUE="$gl_cv_header_errno_h_]$1["
+        ;;
+    esac
+    AC_SUBST($1[_HIDDEN])
+    AC_SUBST($1[_VALUE])
+  fi
+])
+
+dnl Autoconf >= 2.61 has AC_COMPUTE_INT built-in.
+dnl Remove this when we can assume autoconf >= 2.61.
+m4_ifdef([AC_COMPUTE_INT], [], [
+  AC_DEFUN([AC_COMPUTE_INT], [_AC_COMPUTE_INT([$2],[$1],[$3],[$4])])
+])