(keycompare, compare): Replace #ifdef ENABLE_NLS with if (HAVE_SETLOCALE).

(keycompare, compare): Replace #ifdef ENABLE_NLS with if (HAVE_SETLOCALE).
(hard_LC_COLLATE): Define even if ! ENABLE_NLS.
(main): Always initialize hard_LC_COLLATE.
Put initialization next to other locale-related stuff.

Include <langinfo.h> even if ! ENABLE_NLS.
(decimal_point, th_sep): Depend on HAVE_SETLOCALE, not ENABLE_NLS.
(main): Likewise.
(MONTHTAB_CONST): Remove; all uses removed.
(struct_month_cmp, inittables): Do not depend on ENABLE_NLS.
(main): hard_LC_TIME locale does not depend on ENABLE_NLS.