Prevent input stack_max from overflowing

Adds a check to see if recycle stack wouldn't overflow the input stack. If so, then
the items are just put in the recycle slot and they can be taken out again.

circular_saw.lua

@@ -283,7 +283,11 @@ function circular_saw.on_metadata_inventory_put(
 	elseif listname == "recycle" then
 		-- Lets look which shape this represents:
 		local cost = circular_saw:get_cost(inv, stackname)
-		circular_saw:update_inventory(pos, cost * count)
+		local input_stack = inv:get_stack("input", 1)
+		-- check if this would not exceed input itemstack max_stacks
+		if input_stack:get_count() + ((cost * count) / 8) <= input_stack:get_stack_max() then
+			circular_saw:update_inventory(pos, cost * count)
+		end
 	end
 end