Packaged and versioned analysis functions for Shahar's cells

These functions were originally part of RandIgor.

References

Shahar Frechter, Alexander S. Bates, Sina Tootoonian, Michael-John Dolan, James D. Manton, Arian Jamasb, Johannes Kohl, Davi Bock, Gregory S.X.E. Jefferis. bioRxiv 336982 doi: 10.1101/336982