mappings/VegCore-VegBIEN.csv: Added empty mappings for special values (OMIT, etc.), so that they don't show up in **/unmapped_terms.csv. Note that the VegBIEN.csvs only change because the "No join mapping" errors change to "No non-empty join mapping".
mappings/VegCore-VegBIEN.csv: Added empty mappings for special values (OMIT, etc.), so that they don't show up in **/unmapped_terms.csv. Note that the VegBIEN.csvs only change because the "No join mapping" errors change to "No non-empty join mapping".