Support boar luring

[rehmsen]

No description provided.

[rehmsen]

One idea for modelling this:

1. In the map settings, give each resource source a luringDistance, initialDistance and dropOffDistance. Luring distance is what the first worker has to go for each instance of the resource source, initialDistance is what each worker has to go the first time he is assigned to a resource source. dropOffDistance is the distance he has to go for each trip to drop off.
2. Add a special LuringTask which takes time depeneding on luringDistance, shows up as worker on that resource in the task distribution but does not generate the resource.
3. Only allow assigning to harvest the resource source (boar) when it has been lured.
4. In the resource source settings add a quantity to keep track of how much resource lasts.