Returns a list of all the event or canonical rulesets known
   to DECevent.

   DIRECTORY EVENTS
   DIRECTORY CANONICAL

1  –  EVENTS

   Lists all of the event rulesets that are stored in the event to
   canonical (ETC) knowledge library.

   DIRECTORY EVENTS

2  –  CANONICAL

   Lists all of the canonical rulesets that are stored in the
   canonical to report (CTR) knowledge library.

   DIRECTORY CANONICALS