BibAuthorID: speeds up data cache recreation
BibAuthorID: speeds up data cache recreation

* Replaces lengthy SQL query used when starting data cacher by a much
  more efficient query, helping to speed up WSGI process reloading.

* Uses the same speed up technique when creating new person.

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