Log Message:
-----------
Add note warning that OS X updates usually overwrite /etc/rc.
Modified Files:
--------------
pgsql/doc/src/sgml:
runtime.sgml (r1.297 -> r1.298)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/runtime.sgml.diff?r1=1.297&r2=1.298)