Enable "maintain control numbers" and "record ID as TCN" behavior by default

Enable "maintain control numbers" and "record ID as TCN" behavior by default

Per http://ur1.ca/2bgc4, this behavior hews more closely to the MARC21
specification. Note, however, that duplicate bib detection in the
"Import via Z39.50" interface will be somewhat affected; a more
trustworthy workaround is to include the "Local catalog" in Z39.50 searches to
determine if a matching record already exists in the database.

git-svn-id: svn://svn.open-ils.org/ILS/branches/rel_2_0@18694 dcc99617-32d9-48b4-a31d-7c20da2025e4