1st draft for MARC biblio deletion.
Still does not work well, but at least, Biblio.pm compiles & it should'nt break too many things
(Note the trash in the MARCdetail, but don't use it, please :-) )
* fix : the marc subfield was called "tag" in the template. was working nice, but tricky.
* improvment : on each MARC value is now a little finder. If you click on the finder, it will auto-search all biblios with the corresponding value. Very useful to find everything written by an author, or every books from a collection.