* NEWS: In xstrtol, remove STRTOL_FATAL_ERROR and add xstrtol_fatal.

* NEWS: In xstrtol, remove STRTOL_FATAL_ERROR and add xstrtol_fatal.
* lib/xstrtol.h: Don't include exitfail.h; that's now internal to
xstrtol.c.  Include getopt.h, since xstrtol_fatal's signature
depends on it.
(xstrtol_error): Remove.
(xstrtol_fatal): New decl, replacing the functionality of xstrtol_error
but with a different signature.
(ATTRIBUTE_NORETURN, __attribute__): New macros.
* lib/xstrtol-error.c: Include exitfail.h.
(xstrtol_fatal): New function, with a different signature from the
old xstrtol_error, so that the caller need not worry about passing
in an exit status, or about storage management of the option argument.
(xstrtol_error): Now a static function.  Redo signature to
implement xstrtol_fatal.  Output the correct number of hyphens in
front of the option so that the caller need not worry about
storage management.
(N_): New macro.
(_): Remove; not used now.
* modules/xstrtol: Depend on getopt.
* tests/test-xstrtol.c (main): Use new xstrtol_error function instead
of old STRTOL_FATAL_ERROR macro.
* tests/test-xstrtol.sh (t-xstrtol.xo): Adjust to match new behavior
of test program.