PVLAN : Implementing PVLAN deployment capability for VMware deployments in cloudstack.
CLOUDSTACK-2056: DeploymentPlanner choice via ServiceOffering

- Changes merged from planner_reserve branch
- Exposing deploymentplanner as an optional parameter while creating a service offering
- changes to DeploymentPlanningManagerImpl to make sure host reserve-release happens between conflicting planner usages.
Unit test does not use this file anymore.