This diff removes CoordinateRestraint and adds SphereRestraint which
Don't you mean SphericalRestraint?
restraints a point's distance to a fixed point. It also makes the
vectori to Int change. The XYZ decorators patch is also attached again
as the previous version didn't quite split things right (I had needed to
add methods to Particle.h to changed the optimized status of a float).
Looks more or less OK, although I'm sure it'll break Restrainer. (But
that can be fixed at some later point.) But your patch seems to be