Log Message:
-----------
Add documentation example of using interval multiplication with 'days'.
Backpatch to 8.1.X.
Modified Files:
--------------
pgsql/doc/src/sgml:
func.sgml (r1.299 -> r1.300)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/func.sgml.diff?r1=1.299&r2=1.300)