Consider making delta in get_point_location configurable

[janhohenheim]

Right now, from and to in the path finding can be off by up to 0.1 from any vertex in the path mesh. This value seems arbitrary, as the size of the mesh can vary greatly by use case. It seems it would be useful to change this offset, e.g. you could set it to 1 if you knew that your mesh is guaranteed to have a vertex every 1 unit.