title: Does the DSpace Google Scholar mapping for date.issued, available... comply with the expected behaviour
body: <p>I am currently trying to improve the visibility of our Items in Google Scholar. 
  So I had a look at the documentation and the mapping file and found a potential problem: </p>
  
  <p>Google expects the publication date tag, e.g., citation_publication_date ... Don't use it for the date of entry into the repository - that should go into citation_online_date instead. 
  But the DSpace mapping file (google-metadata.properties) does this: <br>
  google.citation_date = dc.date.copyright | dc.date.issued | dc.date.available | dc.date.accessioned </p>
  
  <p>Is this a wrong mapping or did I miss something?</p>
  
  <p>Thanks in advance</p>