README.TXT: Documented how to remove an archived import. Moved archived imports commands from Data import to new section Maintenance of archived imports. Changed "Empty the DB" to "Remove the last import" for clarity, and made the command apply just to the public schema and not also to the functions schemas (reinstalling those is documented under Schema changes).
README.TXT: Documented how to remove an archived import. Moved archived imports commands from Data import to new section Maintenance of archived imports. Changed "Empty the DB" to "Remove the last import" for clarity, and made the command apply just to the public schema and not also to the functions schemas (reinstalling those is documented under Schema changes).