Shells and Periphery (#1327)

Adds Shells. Adds tags. Adds IPC subspecies. Adds HK-47's. Does not add IPC construction.

Beyond the obvious review of shells, the exact stats of the IPC subspecies need review. They were largely an afterthought, and quickly overshadowed by the shell project.

code/modules/projectiles/projectile/bullets.dm

@@ -7,6 +7,7 @@
 	check_armour = "bullet"
 	embed = 1
 	sharp = 1
+	shrapnel_type = /obj/item/weapon/material/shard/shrapnel
 	var/mob_passthrough_check = 0
 
 	muzzle_type = /obj/effect/projectile/bullet/muzzle
@@ -296,3 +297,21 @@
 /obj/item/projectile/bullet/pistol/cap/process()
 	loc = null
 	qdel(src)
+
+/obj/item/projectile/bullet/flechette
+	name = "flechette"
+	icon = 'icons/obj/terminator.dmi'
+	icon_state = "flechette_bullet"
+	damage = 40
+	damage_type = BRUTE
+	check_armour = "bullet"
+	embed = 1
+	sharp = 1
+	penetrating = 1
+
+	muzzle_type = /obj/effect/projectile/pulse_bullet/muzzle
+
+/obj/item/projectile/bullet/flechette/explosive
+	shrapnel_type = /obj/item/weapon/material/shard/shrapnel/flechette
+	penetrating = 0
+	damage = 10