Rsyslogd in EL-6 and later is set up to use a /etc/rsyslog.d directory
where you can drop files containing configuration fragments.  As we no
longer support EL-5 syslog clients, we can make use of that, instead
of modifying the /etc/rsyslog.conf file, to setup the forwarding of
logs to our central syslog server.

This was originally commit cd8c9399b62e in intserv.