make net in port lists arrays

sim/utility.lua

@@ -66,3 +66,14 @@ function tobitstring(num, len)
 	return bitstring
 end
 
+function array_remove(array, value)
+	for i = 1, #array do
+		local v = array[i]
+		if v==value then
+			array[i] = array[#array]
+			array[#array] = nil
+			return
+		end
+	end
+	error("element not in array")
+end