Refine 'to taxon' and 'of organism' relations

[ramonawalls]

Because of organism and to taxon are specific to taxonomic identification process, I think they belong in BCO.

The to Taxon relation specifies dwc:Taxon (http://rs.tdwg.org/dwc/terms/Taxon) as the domain and identification assertion as the range, so it is pretty specific to biodiversity. Similar of of organism. Therefore we should make the labels more specific.

We should consider adding an OBO library compliant class to PCO for taxon (as a collection of organisms), which BCO could then assert is equivalent to dwc:Taxon in an extension. This would be similar to what we have done for organismal entity.

Recommended new labels:

of organism change to identification assertion of organism

to taxon change to identification assertion to taxon