Support for user-chosen fields in Excel output.
Support for user-chosen fields in Excel output.

Parameter 'ot' is passed to the create_excel() function so that we can print fields user is interested in.

tiborsimko/invenio-records,inveniosoftware/invenio-search,inveniosoftware/invenio-search,inveniosoftware/invenio-records,tiborsimko/invenio-search,tiborsimko/invenio-records,inveniosoftware/invenio-records,tiborsimko/invenio-search