Inspired by work by Chris Cormack, move several base Zebra
configuration files to two new directories under etc/zebradb:
lang_defs - language-specific settings (e.g., French and English)
marc_defs - MARC format-specific settings (e.g., MARC21 & UNIMARC)
Installer will query user for language and MARC format and
copy the inital Zebra configs accordingly.
