Add a MaxMonsterCount # option

[Spaceman333]

Would be super useful if I could set a max amount for monsters on a level, after they've been multiplied or divided, so it would never exceed that number.

MaxMonsterCount = 100

So lets say a level has 140, 350 or 1020 monsters, that setting would reduce it to only 100 monsters.

This would be excellent for making maps have better performance, less insanity on maps that already have way more monsters than other levels and allow a more consistent level-to-level experience.

Ideally it would be a number field, but can also be a slider.