WavePacket 0.2.4 released

I just released the next C++-version of WavePacket. Some excerpts from the NEWS file:

• renamed some key classes to disentangle the concept "operator" from "expression/equation/Liouvillian". The new naming system is hopefully much more intuitive. See this blog post for the explanations.
• The Python interface can be installed as a regular Python module. There are still some loose ends here and there, but it works.
• added a couple new demos
  • highlighted demo that explains how to setup thermal states (propagation in imaginary time, random wave functions etc.). See here.
  • demo that uses multiple electronic states (MolElectronic/OH/1 and 2)
  • unfinished demo that sets up a Lindblad relaxation (MolVibration/OH/3)
• improved several PropagationObservers
  • LoggingObserver deals correctly with multiple electronic states
  • Plot1DObserver is way easier to setup, and can plot output for multiple electronic states
• added a projection operator
• some other minor fixes and improvements