Log Message:
-----------
Update SET CONSTRAINTS reference page --- it failed to mention EXCLUDE
constraints and was lacking a couple of other interesting details.
Modified Files:
--------------
pgsql/doc/src/sgml/ref:
set_constraints.sgml (r1.17 -> r1.18)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/set_constraints.sgml?r1=1.17&r2=1.18)