Includes a new config entry for the maximum message length.

This fixes the components not disappearing when doing that.

This prevents that most (but not all) messages are highlighted in private conversations. Now all messages should look normal and thus the conversation much more natural.

If they are used on a server the message prefix would need to be added.

As ist seems to be a base class that is not used directly. We do not need to check for it but only for buttons, selects and the different commands.