- make object which outputs previous and next files

- make patch close itself, otherwise:
   - upon [loadbang], wait, then close previous patch

- in pure_data_files.pd, make the patch create [pd clone] dynamically,
  probably like how send_messages_to_pd.pd does it.

- in pure_data_files.pd, make the patch reset itself once it finishes the
  clone. (remember that [pd clone] has to be the last object.)