Log Message:
-----------
Add SGT (Singapore time) to the default list of known timezone
abbreviations. It doesn't conflict with any other abbreviation
so there seems no reason not to include it. Per a recent gripe.
Modified Files:
--------------
pgsql/src/timezone/tznames:
Default (r1.5 -> r1.6)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/timezone/tznames/Default?r1=1.5&r2=1.6)