BibMerge: delete duplicate record first

* When merging and deleting records, do first submit the deleted
  one such that any possible identifier that would result in a
  duplicate are removed first, before updating the remaining
  record.  (closes #1645)

Signed-off-by: Jerome Caffaro <jerome.caffaro@cern.ch>
Reviewed-by: Tibor Simko <tibor.simko@cern.ch>
OAIHarvest: configurable selective post-processing

* Allow to selectively apply post-processing phases to each
  individual harvested record. To do so override function
  oai_harvest_templates.tmpl_should_process_record_with_mode().
  (closes #1477)

Signed-off-by: Jerome Caffaro <jerome.caffaro@cern.ch>
Acked-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
OAIHarvest: consider source_id for selective post-processing

* Added source_id parameter to function
  oai_harvest_templates.tmpl_should_process_record_with_mode()
  in order to enable decision based on harvesting source.

Signed-off-by: Jerome Caffaro <jerome.caffaro@cern.ch>
Acked-by: Jan Aage Lavik <jan.age.lavik@cern.ch>