[2021] Make difficulty level influence gamestage.

According to comments in the current gamestages.xml, difficultyBonus is still a factor in gamestage calculation. gameStage = ( playerLevel + daysSurvived ) * difficultyBonus
EDIT: However as Teresa points out, the difficultyBonus is always the same, so never mind.

Originally posted by Teresa: I believe the difficulty bonus for all difficulty levels is the same now. I believe 1.2. This is strictly based off of memory so i could be wrong.

You're correct. My mistake.
difficultyBonus="1.2"