Log Message:
-----------
Update release notes to only use HTML4 entities.
Add URL's to mention proper entity lists.
Modified Files:
--------------
pgsql/doc/src/sgml:
release.sgml (r1.451 -> r1.452)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/release.sgml.diff?r1=1.451&r2=1.452)