Remove hard-wired lists of timezone abbreviations in favor of providing

configuration files that can be altered by a DBA.  The australian_timezones
GUC setting disappears, replaced by a timezone_abbreviations setting (set this
to 'Australia' to get the effect of australian_timezones).  The list of zone
names defined by default has undergone a bit of cleanup, too.  Documentation
still needs some work --- in particular, should we fix Table B-4, or just get
rid of it?  Joachim Wieland, with some editorializing by moi.

src/backend/catalog/system_views.sql

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 1996-2006, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/backend/catalog/system_views.sql,v 1.27 2006/05/19 19:08:26 alvherre Exp $
+ * $PostgreSQL: pgsql/src/backend/catalog/system_views.sql,v 1.28 2006/07/25 03:51:21 tgl Exp $
  */
 
 CREATE VIEW pg_roles AS 
@@ -186,6 +186,11 @@ CREATE RULE pg_settings_n AS
 
 GRANT SELECT, UPDATE ON pg_settings TO PUBLIC;
 
+CREATE VIEW pg_timezonenames AS
+    SELECT *
+    FROM pg_timezonenames() AS T
+    (name text, utc_offset interval, is_dst boolean);
+
 -- Statistics views
 
 CREATE VIEW pg_stat_all_tables AS