Apache cloudstack integration for Stratos

Created two java classes in org.apache.stratos.cloud.controller component.
1. CloudstackPartitionValidator.java - implements PartitionValidator
2. CloudstackIaas.java - Extends Iaas.java

Added cloudstack dependancy to Stratos
Added cloudstack sample configuration to cloud-controller.xml


May be we could make this a warning. Asanka can you please update?