Don't autodetect the locale of numbers and

Don't autodetect the locale of numbers and
months, as this conflicts with POSIX.2 and is tricky to boot.

(FLOATING_COMMA, NLS_STRNCMP, NLS_MAX_GROUPS,
NLS_ONE_CHARACTER_STRING): Remove macros no longer used.

(nls_grouping, nls_fraction_found, nls_month_found, nos_monthtab,
nls_months_collide, nls_keyhead, us_monthtab): Remove variables no
longer used.

(struct nls_keyfield): Remove types no longer used.

(strncoll_s2_readonly, nls_set_fraction, look_for_fraction,
nls_month_is_either_locale, nls_numeric_format): Remove functions no
longer used.

(monthtab): Now has the role that us_monthtab had, but it's const only
if ENABLE_NLS is not defined.

(C_DECIMAL_POINT): Renamed from FLOATING_POINT.  All uses changed.
(MONTHS_PER_YEAR): Renamed from NLS_NUM_MONTHS.  All uses changed.
(struct_month_cmp): Renamed from nls_sort_month_comp.  All uses changed.
Use strcmp, not strcoll, since the user doesn't care about collating
here.

(inittables): Read locale data into monthtab, rather than modifying a
separate month table and futzing with indirection.  Do not worry about
colliding months, since we no longer autodetect month locale.

(fraccompare): Don't set no-longer-used variable nls_fraction_found.

(getmonth): Use strncmp to compare months, since user doesn't care
about collating here.  Fix bug where code incorrectly assumed that
strlen (monthtab[lo].name) == strlen (monthtab[ix].name).

(keycompare, main): Don't autodetect month locale.

(compare): Don't use NLS_MEMCP in code that can't be executed if
need_locale is false, as NLS_MEMCP is equivalent to memcmp in that
case.

(sort, insertkey, main): Don't autodetect numeric locale.