Be able to move over the scene when you are a ghost #129
Description
If one of the two entities does not have a rigid body then there will never be a collision and therefor you should be able to move there.
We can still use the walk over strength to guard from "leaving the scene".
We should also fix the behaviour if already two entities are on a given stop. Now it is impossible to move there. While we should just check all entities to see if one of them "guards" from moving there