Class for taxonomic lists including synonyms, hierarchical ranks,
parent-child relationships, taxon views and taxon traits.
Note that each taxon becomes an identifier, represented by the column
TaxonConceptID in the slot taxonRelations, analogous to a primary key
in a relational database.
This identifier is restricted to an integer in taxlist
and is specific for
the object.
In the same way, each taxon usage name has an identifier in the column
TaxonUsageID, slot taxonNames.
The column ViewID in slot taxonViews is the identifier of the taxon
view.