Log Message:
-----------
Mention that HOT helps with DELETE space reuse.
Modified Files:
--------------
pgsql/doc/src/sgml:
release.sgml (r1.570 -> r1.571)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/release.sgml?r1=1.570&r2=1.571)