The slot had been there forever to address this same problem but only one of the two constructors actually set it, too bad that it was the wrong one...
This is something that normally won't be noticed. But if some actor is spawned on a moving platform, with both thinkers on the same statnum it means that the order of execution is not correct with the platform being done first, resulting in the actor to 'jump' while the platform is moving. To prevent this it is necessary that all sector movers only tick after all actors have completed their thinking turn.
We have to be extremely careful with the player data, because there's just too much code littered around that has certain expectations about what needs to be present and what not.
Obviously, when travelling in a hub, the player_t should be retained from the previous level. But we still have to set player_t::mo to the PlayerPawn from the savegame so that G_UnsnapshotLevel doesn't prematurely delete it and all associated voodoo dolls, because it checks player_t::mo to decide whether a player is valid or not.
The actual deletion of this redundant PlayerPawn should only be done in G_FinishTravel, after the actual player has been fully set up
* do not skip the player_t init when travelling in a hub. The old player may still be needed in some edge cases. This applies only to singleplayer for now. The multiplayer version still needs reviewing. I left it alone because it may shuffle players around which is not wanted when doing hub travelling.
* do not spawn two temp players in G_FinishTravel. Instead handle the case where no player_t::mo can be found gracefully by adding a few nullptr checks. This temp player served no real purpose except for having a valid pointer. The actual start position was retrieved from somewhere else.
- Fixed properties not having the proper indices.
- Use ViewPos-to-actor instead of measuring actor-to-actor.
- Use the actual camera instead of the actor so camera textures can work.
