Salt configuration for fluentd to Elasticsearch

This is a starting point for discussion with a view to changing this salt fluentd configuration to be optional and enabled with a flag during cluster creation time. @jbeda please can you have a look at this and please suggest the best way forward for me to change the config and other programs (kubeup.sh?) to make the fluentd to Elasticsearch optional? Thank you kindly.
I'm not sure we want to put this in kube-up.sh.  There are environments (with the pending rackspace merge) that use 'kube-up' but not salt and they won't get this.

Not sure where to document this stuff.  The implementation is really embedded in each of the cluster scripts.  Perhaps in the GCE getting started page?