Ports the Port of Circuits

Ports PsiOmegaDelta's port of integrated circuits, which has several improvements in code quality.
Ports a few small things like the weakref datum and some macros.

code/game/objects/items/weapons/storage/storage.dm

@@ -630,3 +630,14 @@
 				return ITEMSIZE_COST_HUGE
 			else
 				return ITEMSIZE_COST_NO_CONTAINER
+
+/obj/item/weapon/storage/proc/make_exact_fit()
+	storage_slots = contents.len
+
+	can_hold.Cut()
+	max_w_class = 0
+	max_storage_space = 0
+	for(var/obj/item/I in src)
+		can_hold[I.type]++
+		max_w_class = max(I.w_class, max_w_class)
+		max_storage_space += I.get_storage_cost()