Overhaul mod to speedup the pacing of Doom 3.

\Changes/
-Disabled gibbing in favor of keeping ragdoll corpses throughout the levels.
-Increased despawn delay for decals, corpses, and debris.
-Reduced shotgun and chaingun bullet spread.
-Plasma gun projectile lights cast shadows.
-Doubled Plasmagun projectile velocity.
-Added camera shake to player melee.
-Replaced sprinting with always run.
-Increased shotgun reloading time.
-Increased player movement speed.
-Reduced ammo and health pickups.
-Improved bullet tracer effects.
-Increased pistol fire rate.
-Instant weapon swapping.
-Added rocket boosting.
-Disabled fall damage.