use encoding/json instead of encoding/gob (for performance)
use encoding/json instead of encoding/gob (for performance)

JSON is slightly faster (1.02x), and considering it’s such a small
change… :) Furthermore, JSON is human-readable and well-known, so it’s
even better for introspecting the log.

robustirc/robustirc,robustirc/robustirc,robustirc/robustirc