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/.

lib/argp-ba.c

@@ -0,0 +1,34 @@
+/* Default definition for ARGP_PROGRAM_BUG_ADDRESS.
+   Copyright (C) 1996-1997, 1999, 2009-2012 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Written by Miles Bader <miles@gnu.ai.mit.edu>.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* If set by the user program, it should point to string that is the
+   bug-reporting address for the program.  It will be printed by argp_help if
+   the ARGP_HELP_BUG_ADDR flag is set (as it is by various standard help
+   messages), embedded in a sentence that says something like "Report bugs to
+   ADDR."  */
+const char *argp_program_bug_address
+/* This variable should be zero-initialized.  On most systems, putting it into
+   BSS is sufficient.  Not so on Mac OS X 10.3 and 10.4, see
+   <http://lists.gnu.org/archive/html/bug-gnulib/2009-01/msg00329.html>
+   <http://lists.gnu.org/archive/html/bug-gnulib/2009-08/msg00096.html>.  */
+#if defined __ELF__
+  /* On ELF systems, variables in BSS behave well.  */
+#else
+  = (const char *) 0
+#endif
+  ;