Log Message:
-----------
Sync release notes with CVS HEAD; various editorial improvements.
Modified Files:
--------------
pgsql/doc/src/sgml:
release.sgml (r1.557 -> r1.558)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/release.sgml?r1=1.557&r2=1.558)