Palisade+claim change

[overtyped]

Since you can't put a claim within 5 tiles of another claim, and you can't build/extend a palisade on another persons claim, I don't think it makes sense to allow a palisade to be built/extended within 5 tiles of a claim, since you wouldn't be able to ever claim that palisade anyways. The only benefit I can see to keeping it this way is more griefing opportunities.