Bug 3087 Fix Z39.50 server to return the correct record syntax

Bug 3087 Fix Z39.50 server to return the correct record syntax

Modify Makefile.PL and Zebra configuration files in order to parametrized
biblio record type returned by Zebra Z39.50 server.

How to test:

- Test with a MARC21 and a UNIMARC DB
- Do a new installation
- Search from OPAC
- Search from a Z39.50 client like yaz-client: syntax = MARC21/UNIMARC must be
  choosed
- It was working for MARC21: it continues to work
- It wasn't working for UNIMARC: it works now, both in OPAC and from a Z39.50
  client

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Works fine for MARC21. Frederic looked at UNIMARC. Magnus looked at NORMARC.
GRS1 works okay for me. I still have issues with DOM, but they are not directly related to changes in this patch.
A followup is still needed for packaging (debian/templates).

Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>