Add class to install and configure the Route53 DNS plugin for OpenShift

This change adds a puppet class to install and configure the Route53 DNS plugin for OpenShift.

It adds three variables to the openshift_origin global hash:

* ::openshift_origin::aws_zoneid - the Route53 zone ID hash string for the dynamic zone
* ::openshift_origin::aws_access_key_id - the user's AWS access key ID for their AWS account
* ::openshift_origin:aws_secret_key - the user's AWS authentication secret for their AWS account

This class can be used two ways.  It can be a parameterized class or it can pull values from the ::openshift_origin scope.

class {'openshift_origin::plugins::dns::route53': }

Uses ::openshift_origin::aws_zoneid
          ::openshift_origin::aws_access_key_id
          ::openshift_origin::aws_secret_key

Or as a parameterized class:

class{'openshift_origin::plugins::dns::route53:
  zoneid => '',
 access_key_id => '',
 secret_key => ''
}