Improved README.md (added a section related to settings and other related to configuration)
Added a new feature which allow the execute commands only in "private"
registerCommand(cmd, callback, help, onlyPrivate) has a new parameter "onlyPrivate" to control this.
Added getenv as dependency to parse env variables.
Added a feature to ignore some nicks. The bot use the 'BLACKLISTED_NICKS' env variable to get the list of nick to ignore. This variable is a comma-separated string with the nicks.
Added callback for IRC 'error' messages in index.js to avoid crashes instead of that just log the message to the console.