Final hackathon ontology deliverable

- [x] Create namespace for the part of the ontology that is BONSAI-specific (i.e., which does not reside elsewhere): [purl.org](http://purl.org/) does not work for now, so we need to create something temporary
- [x] Provide RDF schema
- [ ] Add OWL restrictions and inference rules
- [x] Create a "proper" ontology with a graphical representation.
- [x] Coordinate classifications for activities and flow-objects (including biosphere flows) with [correspondence tables group](https://github.com/BONSAMURAIS/Correspondence-tables)
- [x] Place final ontology and RDF schema on this or new repo
- [x] Link from wiki to github repo and provide also here any arguments for choices made or alternatives considered
- [x] Provide schema for Flow Properties (e.g., balanceable properties)
- [x] Provide schema for property relation (a.k.a reference unit)

Review the unchecked OWL restrictions and inference rules item against the completed RDF schema and ontology deliverables in this repository. Read the linked Correspondence-tables project and the wiki context before defining the remaining scope; done means the restrictions and rules are added and the final ontology deliverables are complete.

Written by the indexing model from the issue text.