add TIB Hannover records to Math and Math-Themen services

* query the catalogue by using GVK and restricting tho library ID 0089
** GVK has an MSC index, but TIB OPAC has not
* create a »virtual« database gvk-tib for that
make GVK links for opac-de-7 open the Göttingen holdings
add extra search keys for GBV SRU
remove ciando.com URLs from records

usually they don’t seem to work and just litter up the display
use MSCs from arXiv records