Add option to create densse_store of any resource

[sanslash332]

Will be veri interesting that the mechanic of the dense forest can be applied to any resource to block paths with any kind of recolectable things.

Like wood, dirt, snow, etc

Maybe add a extra flag to the definition of the resourse-deposits to indicate that it is able to dense a square, and how many of them do you need to put on ttwo squares to block the path between them. Like you do with the forest.

That will be awesome.