XD-3078: Module redeploy to reconnected containers
Modified ContainerListener as follows:
1. Handling of departed containers has been placed into
a Runnable. This Runnable (DepartedContainerDeployer)
is scheduled for execution when a container departs.
2. DepartedContainerDeployer is also scheduled on a
regular basis to ensure that departed containers
are processed in cases where an event for the
departed container was not raised. This may happen
if the admin server is disconnected from ZooKeeper.
