#363
- LifecycleEventHandler: added listenersToRemove and workers field.
Changed implementation of listeners
- LifecycleEventHandler: added synchronization of listeners to the
addLifecycleListener method
- LifecycleEventHandler: removeLifecycleListener reworked to support
delayed removal
- LifecycleEventHandler: fireEventOccurred added performListenersRemoval
and adjusting of workers value