Log Message:
-----------
Mention that PAM requires the user already exist in the database, per
Dick Davies.
Modified Files:
--------------
pgsql/doc/src/sgml:
client-auth.sgml (r1.76 -> r1.77)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/client-auth.sgml.diff?r1=1.76&r2=1.77)