Add mention of rules/triggers:

> * Add MERGE command that does UPDATE, or on failure, INSERT (rules, triggers?)

doc/TODO

 TODO list for PostgreSQL
 ========================
-Last updated:		Sun May  9 23:58:19 EDT 2004
+Last updated:		Tue May 11 09:44:01 EDT 2004
 
 Current maintainer:	Bruce Momjian (pgman@candle.pha.pa.us)
 
@@ -187,7 +187,7 @@ Commands
 * Have pg_ctl look at PGHOST in case it is a socket directory
 * Allow column-level privileges
 * Add a session mode to warn about non-standard SQL usage
-* Add MERGE command that does UPDATE, or on failure, INSERT
+* Add MERGE command that does UPDATE, or on failure, INSERT (rules, triggers?)
 
 * ALTER
 	o -ALTER TABLE ADD COLUMN does not honor DEFAULT and non-CHECK CONSTRAINT