EventJobManager should not re-throw EnhancementException

The EventJobManager currently caches and re-throws all Exceptions other than a SecurityException. This is not a good behavior as this means that also ChainException and EnhancementEngineException thrown during the processing get wrapped within a new ChainException created by the EventJobManager.

This behavior needs to be changed so that only none EnhancementExceptions are wrapped by a ChainException.