mappings/VegCore-VegBIEN.csv: Map locationID to place.placecode instead when geovalidation columns are provided

mappings/VegCore-VegBIEN.csv: accepted* taxonlabel: Removed ancestor hierarchy because this is populated, in much greater detail, when the accepted name is imported as an input name and the TNRS-parsed components are available

sql.py: distinct_table(): Use DISTINCT ON instead of a unique index and insert_select()'s ignore mode to remove duplicate rows. This uses whichever sorting method PostgreSQL deems to be fastest instead of requiring the use of a B-tree index. Since most of the slower operations in TNRS's import are distinct_table() calls, this should speed up the TNRS import, which is a bottleneck for the DB import as a whole because the TNRS import must complete before other datasources can be imported.

sql.py: distinct_table(): Changed comment about distinct_on column index to include just the input table, so that the function does not guarantee a unique index on the output table's distinct_on columns

mappings/VegCore.csv: Added acceptedCountry, acceptedStateProvince, acceptedDecimalLatitude/Longitude

mappings/VegCore.csv: Renamed latLongValid, latLongInvalid to georeferenceValid, georeferenceInvalid to correspond to DwC term georeferenceVerificationStatus

mappings/VegCore.csv: Added latLongValid, latLongInvalid, latLongInCountry, latLongInStateProvince

input.Makefile: Staging tables installation: Treat any .sql file whose name contains (not just ends with) "schema" as a schema file and sort it before other .sql files

schemas/vegbien.sql: Functions containing UPDATE statements: Use quote_nullable() instead of quote_literal() to properly encode NULL values

schemas/vegbien.sql: Functions containing UPDATE statements: Use PL/pgSQL's EXECUTE statement to avoid caching query plans. This is necessary because as the table grows over time, the optimal query plan may change.