pgsql: suppress_redundant_updates_trigger function.

Log Message:
-----------
suppress_redundant_updates_trigger function.

Modified Files:
--------------
pgsql/doc/src/sgml:
func.sgml (r1.452 -> r1.453)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/func.sgml?r1=1.452&r2=1.453)
pgsql/src/backend/utils/adt:
Makefile (r1.69 -> r1.70)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/Makefile?r1=1.69&r2=1.70)
pgsql/src/include/catalog:
pg_proc.h (r1.521 -> r1.522)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_proc.h?r1=1.521&r2=1.522)
pgsql/src/include/utils:
builtins.h (r1.325 -> r1.326)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/builtins.h?r1=1.325&r2=1.326)
pgsql/src/test/regress/expected:
triggers.out (r1.24 -> r1.25)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/triggers.out?r1=1.24&r2=1.25)
pgsql/src/test/regress/sql:
triggers.sql (r1.13 -> r1.14)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/triggers.sql?r1=1.13&r2=1.14)

Added Files:
-----------
pgsql/src/backend/utils/adt:
trigfuncs.c (r1.1)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/trigfuncs.c?rev=1.1&content-type=text/x-cvsweb-markup)