||Interface for workflow entities that provide meta data.
PayloadMap is listening to workflow events (started,
terminated, completed and manages a payload map (only JCR_PATH payloads)
in order to enable quick lookup for nodes/resources which might be subject
of a workflow..
WorkflowService is the main entry point for accessing the
WorkflowSession class provides all functionality
(depending on the users rights) for managing
Workflow instances and their execution.