utils: changes to multiple affiliations in nations field

* It is now possible to have multiple affiliations in the fields
  100__w or 700__w

* In case of Switerland and CERN in one affiliation, Switerland will
  be dropped.

Signed-off-by: Martin Vesper <martin.vesper@cern.ch>
Merge pull request #81 from mvesper/add_nations_field_in_harvesting_kit

utils: changes to multiple affiliations in nations field