MemoryLeakFix

Aims to solve bugs related to objects not being cleared when they should. Currently fixes a few things:

• Enemy corpse disappearing effects not being re-used or destroyed
  • Might be a significant contributor to degrading performance when playing for a long time?
• Shooter bug
• A few sound players not being cleared
• Several objects not being cleaned up when an enemy died or the level ended
• Inefficient IRF rendering