Log Message:
-----------
Update back-branch release notes.
Tags:
----
REL8_1_STABLE
Modified Files:
--------------
pgsql/doc/src/sgml:
release.sgml (r1.400.2.56 -> r1.400.2.57)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/release.sgml?r1=1.400.2.56&r2=1.400.2.57)