lib/runscripts/table.run: map_table(): create the map table as a persistent table in the temp schema, so that its contents can be viewed for debugging

schemas/util.sql: added drop_table()

schemas/util.sql: set_col_names(): don't perform rename if the name is not changing, to avoid cluttering the debug output with unnecessary queries

lib/runscripts/table.run: use new util.set_col_names_with_metadata() instead of util.set_col_names() so that metadata values (beginning with : ) are automatically mapped to constant columns rather than needing to add a mk_const_col() call to postprocess.sql for each of them. there are a lot of metadata value entries, especially in the Source/ tables for each datasource, so this will save time in translating the datasources to new-style import. note that this requires disabling the map_filter_insert trigger on the map table to prevent it from filtering out the metadata entries before util.set_col_names_with_metadata() can use them.

bugfix: schemas/util.sql: set_col_names_with_metadata(): need `util.` before mk_const_col(). "to", "from" need to be referenced from row_. substring() needs to start from 2 rather than 1 because PostgreSQL string indexes are 1-based.

schemas/util.sql: try_create(), create_if_not_exists(): use eval() so the executed statement will be echoed for debugging

schemas/util.sql: added set_col_names_with_metadata()

bugfix: lib/sh/sync.sh: upload(): paths: don't dereference the path itself if it's a symlink; instead canonicalize just its parent dir. this allows syncing a specific file which is a symlink, rather than syncing the symlink's target.

lib/sh/util.sh: added canon_dir_rel_path(), which canonicalizes just the parent dir if the path is a symlink, to leave the symlink itself untouched

planning/workflow/validation/: archived BIEN2 validations documents which have been superseded by planning/goals/BIEN3_derived_data_products.docx, to avoid confusion