C4 now explodes on detonation, Stechtkin pistol fix

The Stechtkin pistol now works properly, C4 will now create a small
(Welder tank) sized explosion upon being detonated.
Merge commit '521467fa3e5a0b43a772919a30e460c6958556a7'

Conflicts:
	code/modules/projectiles/guns/projectile/pistol.dm