#22 Add CI demo from Lasser et al.

[Burkhard Schmidt]

A. K. Belyaev, C. Lasser, and G. Trigila
The Journal of Chemical Physics 140, 224108 (2014)
https://doi.org/10.1063/1.4882073

[Burkhard Schmidt]

Also include the generalization to N states, see our third WavePacket paper where we have investigated N=3
http://arxiv.org/abs/1902.05092