representation of an OutputDesignation claim

[Ichthyostega]

Decide on the proper representation (and possibly code it up).

It is clear by now that, in order for a (global) pipe actually to appear as part of the model, two conditions need to be met

• the pipe gets mentioned somewhere as an OutputDesignation (typically this happens in the form of a plug within some placement)
• an object actually claims to root this pipe (typically this should be a child of a BindingMO, i.e. directly within a "timeline")

We need to clarify what this claim is, how it works and how its actually to be represented in the model data.