OVERLORD-136 Fix deadlock with adding a service listener that is dependent upon other services retrieved via the service registry
Merge pull request #101 from objectiser/OVERLORD-136

OVERLORD-136 Fix deadlock with adding a service listener that is depende...
OVERLORD-137 Properly keep track of all services, whether obtained via 'get' methods or service listener, to know when the service should be closed
Merge pull request #102 from objectiser/OVERLORD-137

OVERLORD-137 Properly keep track of all services, whether obtained via '...