- faceBitSet, pointBitSet and faceBoolSet (similar to cellBitSet)
  * allows topo sources in a wider variety of places.
  * With copy or move constructors.

- cylinderToPoint, searchableSurfaceToFace, searchableSurfaceToPoint,
  sphereToFace, sphereToPoint sources

- optional innerRadius for sphere and cylinder sources to treat as hollow.

- support "sets" as well as "set" for cellToCell, faceToFace... sources.

  * convenience and avoids writing the set during processing.