import_all: after_import(): Added `make backups/vegbien.$version.backup/test`

sql.py: DbConn._db(): search_path: Don't append the existing search_path, because it usually includes the public schema, which is now different from the schema being imported into. This fixes a bug where sql.function_exists() would find public-schema functions in both the public schema and the import's schema because both were in the search_path, causing a DuplicateException "more than one function named ...". Note that the elements of the existing search_path are no longer needed now that vegbien_dest's $schemas includes $public. Also note that if an instance of DbConn does not specify the schemas param, the existing search_path will be left as-is rather than overwritten with an empty list.

README.TXT: Data import: recording the import times in inputs/import.stats.xls: Added step to determine the import date using import_date

import_date: Added note that Mac and Linux differ in the order they sort the logs in

README.TXT: Data import: recording the import times in inputs/import.stats.xls: Updated pattern for new log filename format

README.TXT: Data import: recording the import times in inputs/import.stats.xls: Removed extra ./ before bin/import_times

import_date: Added note that the time this outputs is the time the first special input finished importing. The import itself generally starts a few minutes before that, and the exact time is in that import's public schema comment.

import_date: Removed duplicate Usage message at top of file, which is repeated in the Usage message provided when the program is run with no arguments

Added import_date

Added mtime