Low ammo version 2 addon

I didn't really like how much ammo you were able to carry for the mini gun/rifle, so I reduced the max ammo count to 400. This will give players a reason not to always fall back on the mini gun. In purist mode, the shotgun pickups was too much (10 shells!) so I lowered enemy shotgun pickups to 4, just like in the original game. In both purist and regular modes, the shotgun pickups in the environments now give 8 instead of 10. Rest of the weapons were untouched.