Player death audio refactored

Refactored players to play death audio via faction instead of via
controller.
Scripts organized in folders

Scripts folder was getting bloated. Now each script has been moved to a
subfolder as to make everything more organized.

May organized scripts by namespaces later.
Shooting audio overlapping solved

An static variable has been added to shooter. Now before playing the
sound, it checks that it hasn't been played in the last few
milliseconds.