pgsql: Done: o -Add support for day-time syntax, INTERVAL '1

Log Message:
-----------
Done:

     o -Add support for day-time syntax, INTERVAL '1 2:03:04' DAY TO
        SECOND

Modified Files:
--------------
    pgsql/doc:
        TODO (r1.1805 -> r1.1806)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/TODO.diff?r1=1.1805&r2=1.1806)
    pgsql/src/backend/parser:
        gram.y (r2.538 -> r2.539)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/gram.y.diff?r1=2.538&r2=2.539)