Use global class instances instead of modifying the classes
Better logging
Disable save/load stuff (no Heun method for now)
Release the hounds!
Make step size controller clearer
Add safety switch
Fix memory management
Better naming
Fix interactions definitions
Turn on numerical units
Encapsulate line ageing procedure
Forget about threaded plotter
Use unicode axes labels
Allow monitoring of the equilibrium particles
Forget about artificial smoothing of the collision integral
Provide the integration region more precisely
Do a better job handling units and updating particles
Fix matrix elements
Slight refactor