Abbreviated alternative month names (%Ob) also added (bug 10871).

Abbreviated alternative month names (%Ob) also added (bug 10871).

All the previous changes also repeated to support abbreviated
alternative month names.  In most languages which have declension and
need nominative/genitive month names the abbreviated forms for both
cases are the same.  An example where they do differ is May in Russian:
this name is too short to be abbreviated so even the abbreviated form
features the declension suffixes.

	[BZ #10871]
	* locale/C-time.c (_nl_C_LC_TIME): Add abbreviated alternative month
	names, define them as the same as abbreviated month names explicitly.
	* locale/categories.def (LC_TIME): Add ab_alt_mon and wide-ab_alt_mon.
	* locale/langinfo.h: (_NL_ABALTMON_1, _NL_ABALTMON_2, _NL_ABALTMON_3,
	_NL_ABALTMON_4, _NL_ABALTMON_5, _NL_ABALTMON_6, _NL_ABALTMON_7,
	_NL_ABALTMON_8, _NL_ABALTMON_9, _NL_ABALTMON_10, _NL_ABALTMON_11,
	_NL_ABALTMON_12, _NL_WABALTMON_1, _NL_WABALTMON_2, _NL_WABALTMON_3,
	_NL_WABALTMON_4, _NL_WABALTMON_5, _NL_WABALTMON_6, _NL_WABALTMON_7,
	_NL_WABALTMON_8, _NL_WABALTMON_9, _NL_WABALTMON_10, _NL_WABALTMON_11,
	_NL_WABALTMON_12): New enum constants.
	* locale/programs/ld-time.c (struct locale_time_t): Add ab_alt_mon,
	wab_alt_mon, and ab_alt_mon_defined members.
	(time_output): Output ab_alt_mon and wab_alt_mon members.
	(time_read): Read them, initialize them as copies of abmon and wabmon
	respectively if they are missing, initialize ab_alt_mon_defined.
	* locale/programs/locfile-kw.gperf (ab_alt_mon): Define.
	* locale/programs/locfile-kw.h: Regenerate.
	* locale/programs/locfile-token.h (tok_ab_alt_mon): New enum constant.
	* time/Makefile [$(run-built-tests) = yes] (LOCALES): Add es_ES.UTF-8
	and ru_RU.UTF-8.
	* time/strftime_l.c (a_altmonth, aam_len): New macros.
	[!COMPILE_WIDE] (ABALTMON_1): New macro.
	(__strftime_internal): Handle %Ob and %Oh formats.
	* time/strptime_l.c [_LIBC] (ab_alt_month_name): New macro.
	(__strptime_internal): Handle %Ob and %Oh formats.
	* time/tst-strptime.c (day_tests): Add more tests to parse different
	forms of month names including the new %Ob format specifier.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>