Players sitting out are now correctly excluded from hand history participants

Previously, when someone was sitting out, the recorded positions, starting stacks and opponents could shift away from what actually happened. Sitting-out players are now treated the same way as in dealing and blind handling, and are excluded from the seats and blinds recreated in replays.

As a result, positions and winnings shown when you look back at a hand now match the real hand. Players who folded mid-hand are still counted as participants, and hand histories already saved are not recalculated.