schemas/public_.sql: merged _plots_20_tnrs_input_names, _plots_21_tnrs_output_names into _plots_20_tnrs_names so the input and output names can be compared side-by-side

schemas/vegbien.sql: synced to DB, which adds Source.errors table indexes added in the import

bugfix: schemas/Makefile: `%/install: public_.sql`: also need to replace `public` when preceded by ( , as it is in the validations queries

bugfix: schemas/util.sql: explain2notice_msg_if_can(): don't use util.is_explainable() because the list provided by Postgres (http://www.postgresql.org/docs/9.3/static/sql-explain.html#AEN77691) excludes some query types that are in fact EXPLAIN-able

schemas/public_.sql: _plots_20_tnrs_input_names, _plots_21_tnrs_output_names: added Brad's comments

bugfix: schemas/util.sql: materialize_query(): contents generated from: need to include search_path so query is runnable

schemas/vegbien.sql: _plots_21_tnrs_output_names: use scrubbed_unique_taxon_name (concatenated output name) because this is more similar to the concatenated name used in _plots_20_tnrs_input_names

bugfix: schemas/public_.sql: _plots_21_tnrs_output_names: need to use TNRS output rather than input name

schemas/public_.sql: added _plots_20_tnrs_input_names, _plots_21_tnrs_output_names

schemas/public_.sql: public_validations: schema comment: documented how to run just the output queries on a particular datasource