Changing order of inheritance from:
IRCBot => PluginBot => CronBot => ChannelManagementBot => AdminBot => LoggerBot => AuthBot
to:
IRCBot => PluginBot => AdminBot => CronBot => ChannelManagementBot => LoggerBot => AuthBot

Fiksing PING during JOIN channel
Adding Topic tracking in ChannelManagerBot
PluginBot now handles topic with 2 as returnflag from plugin.
ChannelManagerBot will set topic to the string None if there is no topic
Updating docs to describe variable channel_topic and setting topic