BF-Streams: Systematics for workflows in workflows

[detlefarend]

Description/Motivation
Stream workflows added as tasks to superior workflows still need to be implemented/validated. The following questions and aspects need to be examined:

Task list

• 1. Question: do all workflows share the same (master) shared object (unlike bf.control)?
• 2. If not: what is to be done to hand over instances from task to workflow to task?
• 3. Pooling of senseful workflows
  • 3.1 Boundary-Detector, MinMax-Normalizer
• 4. Suitable howtos

Related issues
#1046

Cross references
Custom method bf.mt.Task._on_finished() and its implementation in class bf.control.ControlWorkflow