Fixed Bug with beign able to remove an Upgrade that's a Reqirement for other installed Upgrades.
Fixed Collector Upgrade.
Closes #23
When you smelt, you want to get the result, not another furnace upgrade
Because if you smelt with it, you will get another furnace upgrade.
Because if you smelt with it, you will get another furnace upgrade.
Because if you smelt with it, you will get another furnace upgrade.
Because if you smelt with it, ...