Fix Slowdown/Speedup Issues

There are some issues with the Slowdown in the game:

• Reset Speedup when Slowdown is applied: When clicking the button to slow the game down again, it takes the game a while to register this. Why???
• Slowdown not working for GameStepDuration 25? Also not working for GSD of 100 and TimeFactorBeforeEvent of 0.025
• implementing actions -> game-engine "freezes" on 146 or 145 (Tamara) Level 3 roughly starts there, 75 (Christiane), amount of actions?
• speedup does not work after level 1 results window
• speedup should be reset when the game is paused