Remove uncommitted units when the ghost service is removed.
Merge pull request #435 from jaycee/clear-unplaced-unit

Remove uncommitted units when the ghost service is removed.

`_destroyQueuedService` attempts to remove all the items associated with the queued ("ghost") service. While it gets the entries for adding the uncommitted units, it doesn't remove the actual units.

This branch remedies that, and updates the test showing it removes queued service to demonstrate it also removes uncommited units.