Update to latest gnulib and gettext versions.

Update to latest gnulib and gettext versions.
* bootstrap (gnulib-modules): Remove hard-locale, stdio-safer.
Add fopen-safer.
(gnulib_files): Add m4/warning.m4.  Don't worry about files
overwritten by autopoint.
Replace gt_INTL_SUBDIR_CORE with an empty body in m4/gettext_gl.m4.
Suppress "id", "ms", "tr" translations for now, since gettext 0.15
rejects them.
Don't use autoreconf; instead, invoke autopoint etc. by hand,
so that we can remove the intl files at a better time.
(intl_files_to_remove): Remove aclocal.m4, since it gets
rebuilt anyway.  Remove m4/inttypes_h.m4, m4/inttypes.m4,
m4/isc-posix.m4, m4/lib-ld.m4, m4/lib-prefix.m4, m4/po.m4,
m4/stdint_h.m4, m4/uintmax_t.m4, m4/ulonglong.m4.
Add m4/inttypes-h.m4, m4/lock.m4, m4/visibility.m4.
Remove datarootdir hack; no longer needed.
* configure.ac: Use gl_WARNING_CFLAGS rather than BISON_WARNING.
(AM_GNU_GETTEXT_VERSION): Bump from 0.12 to 0.15.
* lib/.cvsignore: Remove hard-locale.c, hard-locale.h, strdup.c,
strdup.h.
* m4/.cvsignore: Remove hard-locale.m4, strdup.m4.
* m4/warning.m4: Remove from CVS, since we now use gnulib's version.