minor, provide --top for tf(1)'s idf command to display only the top N idf values

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'feat/tf-idf-topN'

* feat/tf-idf-topN:
  minor, provide --top for tf(1)'s idf command to display only the top N idf values
minor, provide -r|--reverse functionality for tf(1) idf command

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'feat/tf-idf-r'

* feat/tf-idf-r:
  minor, provide -r|--reverse functionality for tf(1) idf command
fix, PEBKAC, actually print the topN hits (reverse or not) per snarf

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'feat/tf-idf-topN'

* feat/tf-idf-topN:
  fix, PEBKAC, actually print the topN hits (reverse or not) per snarf