README documentation updates

Change-Id: Iba0de05caea7a1f0a8055a6139ad3ecaaaa662cd
Tighten up security group port settings for broker and node.

Separate security groups were created for broker and node hosts.
Firewall rules follow documentation:
https://access.redhat.com/site/documentation/en-US/OpenShift_Enterprise\
/2/html/Deployment_Guide/Network_Access.html

Change-Id: If54f9b636e13679372bd566c8cc8dc6a08e4c7d2
Fix parameter constraints syntax

The server flavor constraints were removed since custom flavors
may be defined that are outside the list of default flavors.

Change-Id: Ifa3d5791257a60a2462cdd4d0d5b53a6721bd50e
Delay creating mongo replica set until other broker hosts available

MongoDB requires all members of the replica set be up when
initiating the replica set. This change delays the creation of
the rs until the other brokers have had a chance to reboot. The
openshift.sh script is used by setting the CONF_ACTIONS env var.

Change-Id: Id3d92c4a46b88b1816994c13a2c07dd33709d4d9