message: added StructureElement.Location.areEqual
diff: @@ -39,6 +39,10 @@ namespace Location {
  return !!x && x.kind === 'element-location';
  }
  + export function areEqual(a: Location, b: Location) {
  + return a.unit === b.unit && a.element === b.element
  + }
  +
  const pA = Vec3.zero(), pB = Vec3.zero();
  export function distance(a: Location, b: Location) {
  a.unit.conformation.position(a.element, pA);
  