Added OAI-PMH calculation of remaining records.
Added OAI-PMH calculation of remaining records.

refs #5023

Changed function used to retrieve OAI-PHM update data to include a
count of remaining records to harvest.

artefactual/binder,CENDARI/atom,Surfrdan/atom,artefactual/atom,artefactual/atom,artefactual/binder,Surfrdan/atom,CENDARI/atom,Surfrdan/atom,kyfr59/atom-cg35,kyfr59/atom-cg35,artefactual/atom,artefactual/binder,kyfr59/atom-cg35,artefactual/binder,CENDARI/atom