bibupload: support for strings in utils
bibupload: support for strings in utils

* Adds support for strings instead of only recstruct in
  bibupload_record helper function.

Signed-off-by: Lars Holm Nielsen <7eaffca9f7cd98839b5821d0d23e09ff764b82cd@cern.ch>

inveniosoftware/invenio,inveniosoftware/invenio,tiborsimko/invenio,tiborsimko/invenio