Major Description
In the current InProgressPool we calculate the existing replica numbers for all the containers based on the container reports. But we don't do anything in case of missing replicase.
This patch is the initial step to process the reported data by comparing the reported replica numbers with the state saved in the Mapping database.
I prerefer to do smaller patches instead of one big one, so this patch doesn't solve over/under replcation the problem yet just detect it.
1. It integrates the EventQueue with the scm and makes it available to the ContainerSupervisor (constructor + field changes)
2. In finalizeReconciliation it sends events to compare expected and current replicase (expected replicas are from the ContainerMapping)
3. Will send a new event in case of under/over replication.
Further works are needed to react to the new events and send delete/copy container commands to the datanode. It also requires more information about the current in-progress replication: If we alread asked a new datanode to replicate the container we need to save it to a map to make the call idempotent: on the next container replication we should not request an other replication. I would prefer to put this additional information to the ContainerMapping instead of a new map.