add some concrete examples illustrating the use of the product module

[elsdvlee]

E.g. How do we represent a product produced by a certain manufacturer and composed of 2 other products produced by another manufacturer.
My questions:

• What is the exact different between product model and product object? I think that a product object can e.g. have a serial number, while the product model is the product in general (abstract), so I would like to add more information to the product model, because that information would then apply to all product objects modelled by the product model.
• Why has only the product object components, and not the product model? I would like to express that a product is (in general, always) composed of some other products.
• How do we represent that a product produced by a certain manufacturer? Should this relation always have a start and end date? Is that the start and end date of producing one physical product? Or can we also express that a product in general is produced by a certain manufacturer (optionally indicating when this happened the first time, but probably without end date in many cases)?

[evabl444]

the first bullet was addressed by adding better documentation to the Resource ODP and the Product module. The second bullet is left for future work, since one is a physical object and the other is not. The third bullet can be expressed through the resource relations, so this needs the addition of an example, which is future work.

[evabl444]

Not all bullets covered

[huanyu-li]

Check 2nd and 3rd bullets

[huanyu-li]

To discuss, in general, how many concrete example to include.

[huanyu-li]

Data from cross-domain evaluation scenario has beed added to full module version 0.2.