Renamed DeploymentPlan::IdleVm to Vm

- Models::Vm is now referenced by 'vm_model' variables
- DeploymentPlan::Vm is now referenced by 'vm' variables
- IdleVm.vm renamed to Vm.model for consistancy with other domain objects
- 'idle_vm' now only refers to VMs in/from ResourcePool.idle_vms

Signed-off-by: dmitriy kalinin <dmitriy@pivotallabs.com>
removing unused internal_to hack

Signed-off-by: dmitriy kalinin <dmitriy@pivotallabs.com>
Refactored ResourcePool & Instance

- Removed active_vm_count in favor of adding vms to allocated_vms
- Moved extra_vm_count into ResourcePool from ResourcePool Updater
- Moved bind_existing_instance, apply_partial_vm_state & apply_vm_state into
	Instance
- Added loggers to ResourcePool & Instance
- Refactored several tests to use rspec allow/expect syntax

Signed-off-by: Kris Hicks <krishicks@gmail.com>