basic implemantation of FRBR

what is missing
- handling with URLQueryHelper (mail to VuFind list)
- back - button from FRBR - list to original search list
- do we want facets as part of FRBR - lists?
- FRBR button for full view
- FRBR - button for Basel / Bern? (by now we don't provide so called regional frbr clusters)