Sound additions for DeadGuy

Adds and implements 4 new death sounds (generated by distorting noise
waves and square waves, then dropping the sample rate.)
Also includes a light impact sound for corpses hitting the ground.

Why? Because the same 2 death sounds can get repetitive. (aka: they sound weird)

Example: http://youtu.be/HQW0aJ5nUsI
(Do ignore the aiming sprites, they are for the bots)