Fixes certain guns being unremovable due to unloading ammo taking
precedence over picking up. Also adds on-back icon for the merc sniper
which is just a copy of the LWAP's.
Tweaks syringe gun and dart gun, renames syringe gun cartridges and makes them printable.
Adjusts penetration so that passing through mobs happens with a probability that scales with damage.
Adds a .45 signal pistol to the HoP's closet and a 9mm one to the mercenary shuttle.
Makes syringe guns a type of launcher gun, and removes the hack
projectile.
Also moves syringe and dart gun source files into the modules/projectile
folder.