[PATCH] Add the info on mods in the saved game metadata

[mimo]

Here is a small patch to add that info. In addition, when opening the load game window, only the ones compatible with the current mod are shown (although a check box allows to show all saved games if needed).

[historic_bruno]

It seems to me like the best way to handle saved games and mods would be to show all saved games, and offer to load/unload the mods needed for each game based on the metadata. Otherwise the player still has to apply the same mod(s) in the same order to be able to use the saved games, but there's not even a way to do that in-game.

I think we should make mods as seamless and nice as possible, so I could envision a dialog prompting the user to load the mods necessary to play the game, if needed, or continue with possible conflicts (useful for testing and e.g UI only mods that won't conflict with saved games). Possibly the mods would be loaded temporarily to play the game, then reverted back to the previous mods afterward.

Another issue to consider is how to handle mod versions, separate from engine version, but that falls more under #2361.

[mimo]

I fully agree that hotloading of mods would be the solution, but that's not yet available. This patch (which regroup #2361 and #2385) is rather to let the player know which saved games needs a mod, or which ones are no more compatible with its current version.

In this new version, I now display all saved games, but with different colors to differentiate them (red=incompatible version and orange=different mod) as seen in the load1.png. And then if you try to load an incompatible mod, a warning window is opened as seen in load2.png.

[mimo]

In 14630:

check version and mods before loading a file, fixes #2361 and #2385.