Primo: make data extraction slightly more general

Philipp Zumstein, 09/12/2014 15:43:
> I don't think that is a good idea. The PNX section |search| is for the
> retrieval and therefore contains a lot of different name forms normal.
> For example in our catalogue (MAN_ALEPH001271912), we have over 100
> different name variants for "Goethe" e.g. "Koet'e, Yohan Polp'ŭgang
> p'on" and they are all saved in |<creatorcontrib>| fields in the
> |<search>| section of the PNX. They should definitely not imported as
> different authors.

Makes sense to me, I'll remove in a followup. Other fields, which may be 
absent in //display, are IMHO worth fetching.