Azure: suspending a node also deallocates it

(Note that this is about the "classic" azurecompute provider, not about azurecompute-arm.)

The AzureComputeServiceAdapter.suspend calls the VirtualMachineApi.shutdown method with a parameter of StoppedDeallocated. Per https://msdn.microsoft.com/en-us/library/jj157195, this parameter makes Azure release all the resources used by the VM. This causes the suspend operation to take a lot of time and any other following resume will also take a lot of time.

I think there should be an option that would cause AzureComputeServiceAdapter.suspend to call the VirtualMachineApi.shutdown method with a parameter of Stopped. That way, suspending and resuming are much faster.

Tearing down the VM entirely (i.e. destroyNode) would still always use StoppedDeallocated.