Bug 11297: Add support for custom PQF attributes for Z39.50 server searches.

Bug 11297: Add support for custom PQF attributes for Z39.50 server searches.

Adds the "Attributes" field to z3950 servers.

The feature here is not quite de same.

In the old patches, the attributes were applied to individual query parts if the part already contains "@attr" and the additionnal attribute is not already in the query part.

Here, the content of the new field is prepended to all PQF queries sent to the server.

This new way of doing is simpler and works for the sponsor.

Test plan:
 I) Apply the patch
II) Run updatedatabase.pl

1) Add a new z3950 server with the following parameters:
Hostname : catalogue.banq.qc.ca
Port     : 210
Database : IRIS
Syntax   : Marc21

2) Perform a z3950 search on that server.
    Keyword (Any) : egypt
2.1) Nothing Found.

3) Add attributes on the server administration page
    @attr 4=1

4) Perform the same z3950 search
4.1) A lot of results

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>