[tz] Proposed update to the tz package files

[Robert Elz]

The combination of an accidental change to the Makefile in tzcode2012a
that was never intended to be released, and the change of the summer time
start date for Cuba, that we discovered just too late for 2012a
(and the stray extra tab in zone.tab) has led me to the conclusion
that we need 2012b very soon - like today...

There will be both code & data files - the sole change in the code is
to return the Makefile to the exact same version it had in 2011i, which
was what it was supposed to be in 2012a.

A diff of the data change from 2012a to (what will probably become) 2012b
is appended.

The only real change is to the start date for summer time in Cuba this year.
The end date is not yet certain, so I'll just leave it as we have it
(last Sun in Oct) and we'll see what happens in September or October
(probably).   Since there is no discernable pattern to the start dates,
I'm also proposing leaving that for 2013 as we had assumed it would be
for 2012 (second Sunday in March).  It has been that more years recently
than anything else (just not last year, or this year, but they've not been
the same either.)

The excess tab from the zone.tab file is also gone.

For anyone considering upgrading their system to 2012a, who hasn't already
done it, I'd advise waiting on 2012b, it is not going to be a long wait.

kre

--- northamerica	2012/03/01 11:22:55	1.5
+++ northamerica	2012/03/01 20:46:07
@@ -1,5 +1,5 @@
 # <pre>
-# @(#)northamerica	8.52
+# @(#)northamerica	8.53
 # This file is in the public domain, so clarified as of
 # 2009-05-17 by Arthur David Olson.
 
@@ -2820,8 +2820,9 @@
 Rule	Cuba	2009	2010	-	Mar	Sun>=8	0:00s	1:00	D
 Rule	Cuba	2011	only	-	Mar	Sun>=15	0:00s	1:00	D
 Rule	Cuba	2011	only	-	Nov	13	0:00s	0	S
-Rule	Cuba	2012	max	-	Mar	Sun>=8	0:00s	1:00	D
+Rule	Cuba	2012	only	-	Apr	1	0:00s	1:00	D
 Rule	Cuba	2012	max	-	Oct	lastSun	0:00s	0	S
+Rule	Cuba	2013	max	-	Mar	Sun>=8	0:00s	1:00	D
 
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	America/Havana	-5:29:28 -	LMT	1890
--- zone.tab	2012/03/01 11:26:34	1.6
+++ zone.tab	2012/03/01 15:30:24
@@ -131,7 +131,7 @@
 CA	+690650-1050310	America/Cambridge_Bay	Mountain Time - west Nunavut
 CA	+6227-11421	America/Yellowknife	Mountain Time - central Northwest Territories
 CA	+682059-1334300	America/Inuvik	Mountain Time - west Northwest Territories
-CA	+4906-11631	America/Creston		Mountain Standard Time - Creston, British Columbia
+CA	+4906-11631	America/Creston	Mountain Standard Time - Creston, British Columbia
 CA	+5946-12014	America/Dawson_Creek	Mountain Standard Time - Dawson Creek & Fort Saint John, British Columbia
 CA	+4916-12307	America/Vancouver	Pacific Time - west British Columbia
 CA	+6043-13503	America/Whitehorse	Pacific Time - south Yukon