* NEWS: Describe interface changes to human, xstrtol.

* NEWS: Describe interface changes to human, xstrtol.
* lib/human.h: Include <xstrtol.h>.
(human_options): Return enum strtol_error, not int.  Remove
bool arg; take int * instead.
* lib/human.c: Don't include "gettext.h".
(_): Remove; no longer used.
Don't include <xstrtol.h>, since human.h does it.
(human_options): Adjust to abovementioned interface changes.
Do not report error to stderr; that's now the caller's
responsibility.
* lib/xstrtol.c (main) [defined TESTING_XSTRTO]: Adjust to
interface change.
* lib/xstrtol.h (_STRTOL_ERROR): Take Option, Arg rather than
Str, Argument_type_string.  All uses changed.  Put " argument"
in diagnostics to make them clearer.  Change wording of suffix
message for clarity.
(STRTOL_FATAL_ERROR): Take Option, Arg rather than Str,
Argument_type_string.
(STRTOL_FATAL_WARN): Remove; no longer used.
* modules/human (Depends-on): Remove gettext-h.