Log Message:
-----------
Ooops, let's get the non-null vs null bit right ...
Modified Files:
--------------
pgsql/doc/src/sgml/ref:
create_function.sgml (r1.89 -> r1.90)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/create_function.sgml?r1=1.89&r2=1.90)