Log Message:
-----------
Clarify replication items, and define some terms.
Modified Files:
--------------
pgsql/doc/src/sgml:
failover.sgml (r1.6 -> r1.7)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/failover.sgml.diff?r1=1.6&r2=1.7)