Add of numerous feedback for LG & DG other things

- Addition of an audio feedback when LG is dying (some tweaks to do)
- Modif of the audio feedback of DG getting hit (and the one time
indication)
- Addition of an audio feedback when DG enter sneak mode (crappy sound)
- Addition of an audio feedback when DG enter rush mode (crappy sound)
- Very small heal (3, so 10 seconds of life) when LG get a flower pot
(nice effect when LG get a pot while he is dying)
- Fix of a good portion of the launch stutter (GO not being desactivated
during the first stage of the initialisation)
- Some cleanup in the code here and there and few comments
- +1 spawnpoint for the pot on n°2 and slight modif of the arena to
allow it

Still need a better sound for the continuous hit of the beam on LG and
the pot feedback
Fix of the conflict on proto_01

I forced the add of the scene after doing the same changes (as they were
stated in the commits notes). I don't think it will break anything.