new service "Acquisiton"

[nichtich]

It should first be clarified how this relates to other services, such as Deliver (#2), but it looks like acquisiton (by buying, finding, receiving as gift, occupying etc.) is distinct to Lending, Presentation, Interloan etc.

I wonder why there is no ontology for such shopping events yet.

Acquisition could also be used to model provenance. The Provenance ontology might be connected to this but it looks like it aims at other use cases. See also issue #4 about Creation.