Tractor Mod was temporarily disabled in multiplayer because the game crashes trying to sync the custom Tractor and TractorGarage classes. Fix compatibility with multiplayer.

Possible solution: eliminate the custom classes (so the tractor is just a horse and the garage is just a stable), with separate logic to edit their data (e.g. textures) and behaviour (e.g. update tick tools). Set a flag somewhere in their data so another player's TractorMod knows to do the same. If a player doesn't have TractorMod installed, they'll just see a regular horse and stable.

Done in develop for the upcoming Tractor Mod 4.7.