lib/sh/util.sh: added log-() because it's non-obvious that you would otherwise have to invoke log+() with a negative #

schemas/util.sql: reset_map_table(): drop the table and recreate it instead of just creating it if it doesn't exist, so that any change to the util.map table is propagated to persistent map tables whenever they are reloaded from the map.csv

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.