Furnace and campfire auto stop

No more bags upon bags piling up amongst ever burning furnaces and campfires - they now stop altogether once a single item is ejected. It may be inconvenient, but is aimed at improved server performance. All those burlap sacks piling up and combining outside of every burning furnace across the server adds up.

There were some more drastic changes proposed to furnaces - which we may still see in the future - but for now, furnaces and campfires just stop the moment something ejects.