Add a zone for OpenShift infrastructure if requested

This change allows the openshift_origin class to also create a separate DNS zone for the OpenShift infrastructure hosts.  The caller must provide the zone name, a zone update key (if dynamic updates are enabled) and a set of
hostname/ipaddress pairs for the infrastructure hosts.

This change adds 3 arguments to the openshift_origin class:

* __dns_infrastructure_zone__
 The zone which will contain the OpenShift infrastructure hosts
* __dns_infrastructure_key__
 The DNS update key string
* __dns_infrastructure_names__
 A list of hostname/ipaddress pairs to use to populate the infrastructure zone.

> dns_infrastructure_names => [
>> {hostname => 'broker1', ipaddr => '10.0.0.1'},
 {hostname => 'data1', ipaddr => '10.0.0.2'},
 {hostname => 'message1', ipaddr => '10.0.0.3'},
 {hostname => 'node1', ipaddr => '10.0.0.11'},
],