bugfix: lib/sql_io.py: put_table(): handle_MissingCastException(): when updating join_cols, don't add new entry for join_cols[out_col], only update existing one. this fixes #902 (import bug), and with #902 fixed, #887 (disk space leak) should no longer occur.

bin/import_all: delete_logs(): documented that `trap EXIT` doesn't run until shell exit

bin/import_all: delete_logs(): print when this happens, so it can be verified that it's happening properly

bugfix: bin/import_all: need to run delete_logs manually because `trap EXIT` doesn't run until bg cmds done

bin/import_all: delete_logs: moved testing of whether to delete logs to delete_logs() so that delete_logs() can be run regardless of the $delete_logs setting

bugfix: bin/import_all: delete_logs(): also need to match log filenames when n=""

bugfix: /Makefile: postgres_restart-*: argument to echo always needs quotes

bugfix: /Makefile: $(pg_ctl-*): tell user that if it doesn't work, need to run `rm $(macPostgresDir)/postmaster.pid` and retry

/Makefile: $(pg_ctl-Darwin): documented the pg_ctl version of this command in case `brew services` doesn't work

bugfix: bin/with_all: isset(): need to use `>&- 2>&-` because &> does not work with - as the dest