workflows: task_counter value check

* Checks if the task_counter parameter is a list when saving
  an BibWorkflowObject. It is required to avoid a problem with the
  underlying workflow engine.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
workflows: Holding Pen details fix

* Fixes a problem where the detailed page for Holding Pen
  object caused an exception when information on next/previous
  objects from the table were missing.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
oaiharvester: authorlist extraction task

* Updates post-process task for authorlist extraction to
  properly fall back to the default XSLT stylesheet.

* Adds a check that the script file is found for the filtering
  script task.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
oaiharvester: updates OAI post process

* Improves the logic and documentation of the tasks to
  post-process harvested records to be less error prone.

* Updates some tests with comments and missing logic.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
OAIHarvest: logging creation fix

* Properly sets the OaiHARVESTLOG.date_harvested value when creating
  a log entry by calling datetime.now() in the proper way.

* Removes exception masking in create_oaiharvest_log_str().

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
oaiharvester: record extraction improvement

* Improves the OAI-PMH record extraction to better use namespaces to
  output cleaner data without dummy namespaces.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>