* adding glass to opac marc detail.

* adding glass to opac marc detail.
* changing glasses behaviour : It now appears only on subfields that have a "link" value. Avoid useless glasses and removes nothing. **** WARNING **** : if you don't change you MARC parameters, glasses DISAPPEAR, because no subfields have a link value. So you MUST "reactivate" them manually. If you want to enable the search glass on field 225$a (collection in UNIMARC), just put 225a to "link" field (Koha >> parameters >> framework >> 225 field >> subfield >> modify $a >> enter 225a in link input field (without quotes or anything else)
* fixing bug with libopac