- Add cooldown to delivery quests

- Have the ability to only allow 1 quest in progress instead of all of them.

This is something I've been wanting for a long time. Currently people can just do them over and over racking up a ton of resources. I wish we could make it so they can only do it once per day or something but make it a nice reward. A way to entice people into high PVP spots but not something they can abuse.