mappings/VegX-VegCSV.stems.csv: Mapped VegX plot terms except unique keys

mappings/VegX-VegCSV.stems.csv: Mapped remaining sourceAccessionCode user-defined terms to <VegX-table>.uniqueID

mappings/VegX-VegCSV.stems.csv: Corrected sources of VegX names to point to the appropriate element in veg.xsd, rather than the appropriate type, because the names we used actually came from veg.xsd's top-level elements rather than from the type names

mappings/VegX-VegCSV.stems.csv: Changed plantObservation.sourceAccessionCode to individualOrganismObservation.uniqueID, to be consistent with VegX names. (*source*AccessionCode only applies to an aggregate DB that preserves info from its inputs. accessionCode made less sense, because this field is for the datasource's primary key, which it may or may not consider an accession code.)

mappings/VegX-VegCSV.stems.csv: Mapped aggregateOrganismObservation terms

mappings/VegX-VegCSV.stems.csv: Changed base back to baseSaturation to distinguish this pH-related concept from other meanings of base, and to match VegBank

mappings/DwC2-VegBIEN.specimens.csv: Removed no longer applicable comments, which were from the very first NY/SALVIAS->VegX/VegBank mapping and had been preserved by the map spreadsheet transformation scripts. Note that many comments have been left, because they either provide explanatory information or because we never reached a decision on the questions posed (such as many of Brad's "OMIT" comments).

mappings/VegX-VegCSV.stems.csv: Removed no longer applicable comments, which were from the very first NY/SALVIAS->VegX/VegBank mapping and had been preserved by the map spreadsheet transformation scripts

mappings/VegX-VegCSV.stems.csv: Mapped individualOrganismObservation user-defined terms

Regenerated vegbien.ERD exports