Outdated References: Misbehavior Arbitration Subsystem

[BradleyOlson64]

Mentions of the Misbehavior Arbitration subsystem seem outdated. My impression is that this subsystem was initially intended to handle both disputes of parablock candidate validity and other, easier to punish, forms of misbehavior. Now it seems that those responsibilities are split, with disputes handled by the disputes subsystem and other misbehavior punishment not yet implemented. This should be appropriately reflected in the implementers guide and code comments.