Separates the sharp flag into edge and sharp

Now weapons can properly cause cuts without necessarily having a greater
chance to remove limbs.

Also separates is_sharp, has_edge, and can_puncture.

code/game/objects/structures/inflatable.dm

@@ -110,7 +110,7 @@
 	attackby(obj/item/weapon/W as obj, mob/user as mob)
 		if(!istype(W)) return
 
-		if (is_sharp(W))
+		if (can_puncture(W))
 			visible_message("\red <b>[user] pierces [src] with [W]!</b>")
 			deflate(1)
 		if(W.damtype == BRUTE || W.damtype == BURN)