Revert some zone-to-link changes and add some more; plus related fixes.

Revert zone-to-link changes that changed current time zone
abbreviations.  Add a few more changes, for more consistency.
Make several other fixes discovered while researching this.
* africa (Africa/Accra, Antarctica/Syowa):
* asia (Pacific/Palau):
* australasia (Pacific/Funafuti, Pacific/Majuro, Pacific/Wake)
(Pacific/Wallis, Antarctica/DumontDUrville, Pacific/Chuuk)
(Pacific/Pohnpei):
* northamerica (Pacific/Tahiti):
Remove links, as they are now zones again.
* africa (Africa/Accra, Africa/Maputo):
* antarctica (Antarctica/DumontDUrville, Antarctica/Syowa):
* australasia (Pacific/Tahiti, Pacific/Majuro, Pacific/Chuuk)
(Pacific/Pohnpei, Pacific/Palau, Pacific/Funafuti, Pacific/Wake)
(Pacific/Wallis):
Restore zone.
* africa (Africa/Accra): Assume DST starting in 1920, as per Scott
Keltie & Epstein 1920.
* asia (Asia/Bahrain, Asia/Phnom_Penh, Asia/Kuwait, Asia/Vientiane)
(Asia/Muscat, Asia/Ho_Chi_Minh, Asia/Aden):
* northamerica (America/Antigua, America/Cayman):
Change from zone to link, as these are also closely related.
* africa (Africa/Blantyre, Africa/Bujumbura, Africa/Gaborone)
(Africa/Harare, Africa/Kigali, Africa/Lubumbashi, Africa/Lusaka):
Now links to Africa/Maputo, not Africa/Johannesburg.
* asia (Asia/Riyadh): Change standard-time transition from 1950
to 1947-03-14.  Add commentary citing Hunt 1961 and CAB 1946.
* australasia (Pacific/Chatham): Assume NZST - 45 min. before 1946.
Add commentary about this.
(Pacific/Pago_Pago): UT-11 from 1911 to 1950.
(WS, Pacific/Apia): Use NZ-style abbreviations.
Switch to "WSST" for Western Samoa standard time before 1950.
Add commentary about Samoa before 1950.
* backward (Africa/Asmera, Africa/Timbuktu, Asia/Saigon):
Redo to avoid link-to-link.
* europe (Hungary, Europe/Bucharest): Several pre-1946
corrections: in 1918 the transition out of DST was on 09-16, not
09-29; in 1919 it was on 11-24, not 09-15; in 1945 it was on
11-01, not 11-03; in 1941 the transition to DST was 04-08 not
04-06 at 02:00; and there was no DST in 1920.
(Poland): Add source for 1919.
* southamerica: Add link for America/Antigua.
* NEWS: Document the above.  Add some thanks.
* tz-link.htm, NEWS: Mention the latlong package.

(Thanks to a heads-up from Dirkjan Ochtman.)
Be a bit more consistent about Metlakatla and Resolute abbr and comments.

* northamerica (America/Metlakatla): Use the more-common "PST"
rather than our invented "MeST" for the abbreviation.  Our source
called it "Pacific Time", as did a contemporaneous news report,
and I couldn't find contemporaneous use of "MeST" or of
"Metlakatla Time".  Cite the news report in the commentary,
and quote some Juneau graffiti.
* zone.tab (America/Resolute): Call it Central Time, not Central
Standard Time, since it observes DST now.
(America/Metlakatla): Call it Pacific Standard Time, not
Metlakatla Time.  Mention that it's in Alaska.
* NEWS: Document the above.
* zone.tab: Reorder to put Pacific times together.
New file time.tab, superseding zone.tab

It allows multiple country codes per zone.  Switch code and data to
use the new format, along with the recently-added Crozet Islands entry.
The old zone.tab file is still installed but is deprecated.
The new file uses UTF-8; add commentary saying that iso3166.tab is
planned to change to UTF-8.
* Theory, tzselect.8 (FILES): zone.tab -> time.tab.
* africa (Indian/Alfred_Faure): Remove link.
* antarctica: Mention Possession Island in comments.
* checktab.awk: Add support for checking time.tab.
* iso3166.tab: Mention planned switch to UTF-8.
Update ISO 3166-1 Newsletter from VI-15 to VI-16.
* time.tab: New file.
* tzselect.ksh (zonetabtype): New variable.
Add undocumented -t option, meant for developer testing.
(TZ_ZONE_TABLE): Use zonetabtype.
(output_distances, countries, regions, TZ): Support time.tab format.
(quoted_continents, distance_table, countries, regions)
(TZ, TZ_for_date): Quote shell strings more carefully.
* zone.tab: Refer to time.tab for detailed comments about format.
(Indian/Alfred_Faure): Remove.
* Makefile (TIMETABLES): New macro.
(TABDATA, install, check_tables): Use it.
(check_character_set, check_tables): Check time.tab too.
(check_time_t_alternatives): Use time.tab, not zone.tab.
* NEWS: Document the above.
* europe, NEWS: Give proper credit to George Vernon Hudson

as the inventor of DST.
* europe: Fix spelling in comment.  (Thanks to Christos Zoulas.)
* checktab.awk: Fix typo that prevented catching inks in 'time.tab'.

Also, hoist some code out of a loop.
* Makefile (TZCOBJS), NEWS: Remove localtime.o, asctime.o.

(Thanks to John Cochran.)