documents.json and the three split CSVs, migrated in place by
brenda_references/scripts/migrate_organism_classes.py (d3text 6f3bf40):
archaea and plasmids leave bacteria; bacterial phyla, genera and
"uncultured" names leave other_organisms. Ids and the train/val/test
partition are unchanged except where a move forced a fresh id. The two
noise pools are untouched.
Add the three splits and the linguistics noise pool
