This comes from gnulib 348402f2aac342bc925b7aaea9ee3cc353f427a9 plus
a custom patch to support compilation of arpg in C++11.

* lib/hard-locale.c, lib/hard-locale.h, m4/hard-locale.m4, m4/ltargz.m4:
New files.
* lib/Makefile.am, lib/alloca.in.h, lib/argmatch.c, lib/argmatch.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/c-ctype.h, lib/c-strcase.h, lib/c-strcasecmp.c,
lib/c-strcaseeq.h, lib/c-strncasecmp.c, lib/config.charset,
lib/dirname-lgpl.c, lib/dirname.h, lib/dosname.h, lib/errno.in.h,
lib/error.c, lib/error.h, lib/exitfail.c, lib/exitfail.h,
lib/fcntl.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/gettimeofday.c, lib/hard-locale.h, lib/intprops.h, lib/isatty.c,
lib/itold.c, lib/l...