/README.TXT: Full database import: documented that env vars set before invoking `screen` will be inherited by it, so these steps will work even if they come before `screen`

backups/TNRS.backup.md5: updated

/README.TXT: Full database import: added steps to set a custom version, if the auto-assigned one would cause a collision with the last import

/README.TXT: Full database import: `unset version`: documented that this is needed because it may have been set in the outer shell

fix: lib/sql_io.py: put_table(): don't warn if can't create pkey, because this just indicates that a set-returning function was used. this should get rid of the last of the confusing benign warnings in the test output.

fix: lib/sql.py: flatten(): don't warn if can't create pkey, because this just indicates that a set-returning function was used

lib/sql.py: run_query_into() added add_pkey_warn param to support turning off "could not create unique index" warnings, which are sometimes benign (eg. when using set-returning functions with column-based import)

/README.TXT: Full database import: disk space: updated schema size (315GB)

/README.TXT: Full database import: removed `up` on jupiter because this is done as part of "do steps under Maintenance > "to synchronize vegbiendev, ..."

/README.TXT: Full database import: moved "do steps under Maintenance > "to synchronize vegbiendev, ..." outside of "On local machine" because these steps don't only take place on the local machine