diskimage-builder elements for openshift-origin

These have been used to deploy a working openshift stack.

They pre-install more images than the oz templates, based on the yum
log of extra installs during boot time.

Change-Id: Icb246033964e1388aeebdd4229790acfe0e17718
OpenShiftAutoScaling and OpenShift feature parity.

Updates OpenShiftAutoScaling.template with fixes contained in
OpenShift.template.

Nodes do scale when the hard-coded cfn-push-stats value is raised
above the threshold.

Change-Id: I79051a15a5116034d06fd95b5cc8c3412eda33a8
Additional OpenShiftAutoScaling launch parameters.

- Server flavors for broker and nodes
- Min and max node server counts for autoscaling policy

Change-Id: I70835beca8e29e33c3e8b25cc57d5321a4df7c11