In the API mode, when [] is to be returned, transform it to string, otherwise mod_python gives an internal error.  Also, use argd instead or args consistently.
In the API mode, when [] is to be returned, transform it to string,
otherwise mod_python gives an internal error.  Also, use argd instead
or args consistently.

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