Log Message:
-----------
Update release notes to current.
Modified Files:
--------------
pgsql/doc/src/sgml:
release-9.0.sgml (r2.19 -> r2.20)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/release-9.0.sgml?r1=2.19&r2=2.20)