[abstract>textpreview>other props] in doclist shortContent

It searches for 'abstract' and 'textPreview', these have priority - in
this order. If none of these two were found, it shows a random property
value of the given document (excluding
http://www.w3.org/1999/02/22-rdf-syntax-ns#type and
http://purl.org/dc/terms/title).