Add formatting.strip_colors method for IRC color stripping
Expose cloudbot.log_dir for external usage by plugins
Add support for plugins using the old `commandname <args> -- description` format, detecting it using `doc.split(None, 1)[0].isalpha()`
Add an EventType enum to BaseEvent for allowing different events (JOIN, PART, MESSAGE, KICK, NOTICE) to be separated in a non-IRC-specific manner, not relying on irc_command
Use EventType in ignore plugin
Complete rewrite of log plugin