inputs/import.stats.xls: Updated with new stats from an independent import

schemas/vegbien.sql: Fixed UNIQUE INDEXes that were still using COALESCE to use COALESCE in order to match what sql_gen.EnsureNotNull uses

schemas/vegbien.sql: specimenreplicate: UNIQUE INDEX on catalognumber_dwc: Added collectioncode_dwc so that datasources that specify it in addition to the institution_id (such as aggregators) will not need to have catalognumbers be unique within an institution

inputs/import.stats.xls: Updated with more stats from latest import

inputs/import.stats.xls: Updated with initial stats from latest import. Reformatted to put successive runs of column-based next to each other, so they could be directly compared and so that the row-based data wouldn't need to be duplicated. Added empty-value checks to formulas so that they don't need to be manually deleted when one of their inputs is empty.

input.Makefile: Documentation: import/steps.by_col.sql: Fixed bug where needed to run import in test mode

sql_io.py: put_table(): Don't set pkeys of missing rows to default value if out_table is a SQL function, because then there is already an entry for every row

bin/map: by_col: Reuse existing out_db connection for in_db instead of opening separate connection

sql.py: mk_select(): Replaced newlines with spaces when query is simple enough to fit on one line

db_xml.py: put_table(): Set db.src to help identify the data source in pg_stat_activity