BibTasklets: doctypes fix for consysn

* Adds a filtering on harvesting files based on their
  doctype, converts only files with doctype 'fla', 'add',
  'chp', 'err', 'rev', 'sco', 'ssu' and 'pub'.

Reviewed-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
Signed-off-by Georgios Papoutsakis<georgios.papoutsakis@cern.ch>