BibRank: detailed citations diff

* When bibrank -w citation fails because we lost too many citations,
  displays in the log for each record how many citations they lost.
* Abort bibrank task when the loss for a record is greater than x.
  (x is set in the citation.cfg)
BibRank: do not exit on per record losses

* Updates the per-record citation/reference loss checker to not
  abort updating when too many are lost and insteads warns admins'
  to check this record manually. If too many references are lost
  overall, execution is still aborted.

* If loss is detected a ticket is sent to "CitationLoss" queue for
  CFG_INSPIRE_SITE.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
Reviewed-by: Javier Martin Montull <javier.martin.montull@cern.ch>