Pass the $no_dedup_sentences and $no_vector parameters forward to the process_download_for_extractor() (although they're not actually being used in the ExtractAndVector Gearman worker)
When skipping the "split story into sentences, words and determine language" part of the extraction, report that fact to STDERR
In the extractor code path, don't return or die without logging the reason; in Languages.pm, return undef (instead of an empty array) if it wasn't possible to split given text into sentences