added hidden audio settings to ra/d2k GUI

- video volume
- map music (was shellmap music)
- sound engine
expose hidden Debug settings to ra/d2k GUI

- performance text switch
- performace text update rate
- AI debug messages
- trait report threshold ticks
add hidden MaxFPS settings to ra/d2k GUI
Merge pull request #2745 from Mailaender/more-settings

Add hidden settings to the GUI