Moved the Client.Callback and Worker.Callback interfaces out of the Client and Worker interfaces.
Updated the documentation of the Client and Worker interfaces.
Moved the ClientManager.State and WorkerCoordinator.State enums out of the ClientManager and WorkerCoordinator interfaces.
Removed two occurrences of accidental use of raw types.
Refactored the way ClientCallbacks and the Client.listen method works.
Refactored the way WorkerCallbacks and the Worker.listen method work.
Merge branch 'master' of github.com:golvmopp/sdmapeg
Added partial support for the WorkStealingResponse message type in the worker implementation.