channel mode parser rewrite

The new parser is CHANMODES based as provided by RPL_ISUPPORT and exposes all
parsed data to the IrcClient.OnChannelModeChange event.
fixed indention
fixed event signature of IrcClient.OnChannelModeChange
don't automatically rejoin channels in Reconnect(bool) if AutoRejoin is set to false
fixed duplicate key exception when IRC servers advertise duplicate mode letters