Log Message:
-----------
Update back branch release notes.
Tags:
----
REL8_1_STABLE
Modified Files:
--------------
pgsql/doc/src/sgml:
release.sgml (r1.400.2.20 -> r1.400.2.21)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/release.sgml.diff?r1=1.400.2.20&r2=1.400.2.21)