Compatible old saves wip (not garanted)

So the goal for the next update is to make the new saves of the next versions of the game be usable with further builds.

I'm not quite experienced in that regard but it's probably something rather simple to do, I've got a hint that it may be done with "after_load" but it's not something I've done before. I'm also using ren'py to make the game so if anybody who knows how to do it wants to share some advices I am very open to the idea!

BUT

The only issue being that the game will have time limited events for the main story meaning that if somebody grinded for months on a save from an older version without those events he will be locked out of the story even if he reload his save on the new version. So I'd have to give an option to go back in time when reloading an old save, which isn't quite practical.

This means that without going back in time you'll only be able to do the free roaming scenes. It also means more programation efforts to make sure that doing so wont breaks anything in the code.