Log Message:
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Create 9.0 release notes; keep 9.0-alpha release notes in place.
Modified Files:
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pgsql/doc/src/sgml:
release-9.0.sgml (r2.2 -> r2.3)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/release-9.0.sgml?r1=2.2&r2=2.3)