Setting to adjust the number of autosaves and their frequency

[Ailothaen]

As now, the game keeps 3 autosaves. If I am not mistaken, they are made every 2 minutes, and when one is made, the oldest one is removed to keep the limit at 3.

However, we may want to be able to get back to a point which is further than the oldest autosave (and the latest "manual save" is now way too far behind), for various reasons : replaying a mission, fixing a bad decision taken, correcting a bug-generating condition (happened to me with this problem recently)... For this reason, the number of autosaves would have to be increased.

A good idea for me would be to give players flexibility on how the autosaves are managed. I imagine, in the settings, a slider that would be set by default on 3, but could be adjusted from 0 (completely disables autosaves) from something like 15 or 20 for example. (We could even go further and let people remove the limit if they wish to – they would have to perform the cleanup manually though)

Another opportunity coming with this one is to also implement another slider next to the previous one to configure the frequency of each autosave (1, 2, 3... 15 minutes?)