Some tweaks:

• The sqlknow plugin now uses non-greedy matching, which helps when the value
  being stored is a long sentence using the word "is".
• The sqlknow plugin now supports forgetting ("cbot forget $key"), but only
  deletion by the admin. There's no good reason for that restriction, I guess
  it's just a power trip.
• The CLI backend now has a "/nick" command to test authorization.