vegbien_dest: Added temp to schemas list so the intermediate tables will be created there, where they are easy to remove with `make schemas/temp/reinstall`

main Makefile: Added %/reinstall, which calls the corresponding uninstall and install targets

Added temp schema to store intermediate tables permanently when desired for debugging. It is not part of schemas/all because it should not be remade to include current intermediate tables when remaking other schema exports.

schemas: Moved *.sql.make into Makefile to take advantage of % pattern matching

Removed no longer used schemas/vegbien_empty.sql

main Makefile: Removed empty_db, because `make schemas/reinstall` has the same effect and is simpler

README.TXT: Changed documentation to use make schemas/reinstall to empty the DB, since that command is simpler. Added how to archive the last import.

db_xml.py: put_table(): Removed `if not db.debug_temp` check because that is done by sql.empty_temp()

sql.py: put_table(): Use new empty_temp()

import.stats.xls: Added comments for estimated numbers. Added "," separators to large numbers.