Fix utils.py
Parameter update
Remove 'forces.f90' from Makefile; auto-save params during runs
Change date format in Makefile
These seem to be good values for the Solar wind.

Density at 1AU = 34e12 kg/AU^3 = 6 particles/cm^3
Speed   at 1AU = 100 AU/year   = 470 km/s
Realistic supernova parameters (#7 in paper)
High res simulations with fixed time
Animation script