SignalIntegrity crashes jupyter notebook kernel

[ChrisDaunt1984]

The use of jupyter notebook consistently crashes a jupyter notebook kernel when plotting inline

Steps to repeat

1. Start a jupyter notebook
   2 Import matplotlib.pyplot as plt
2. Import SignalIntegrity
3. perform an calculation
4. plot
5. perform an additional plot and kernel will crash

I believe that SignalIntegrity is resetting some matplotlib setting as it tries to plot externally but hangs and crashes

[PetePupalaikis]

Please fetch the InNextRelease branch and try this again. I believe that this should not happen.
Recently, I made changes such that tkinter is not imported when operating SignalIntegrity either as a library or as a headless project for calculation.
Try it and close this if it is fixed.