Resolve "Octupole magnet strengths are set using the formula for Decapoles"
Closes #653 (closed)
I have made the code more generic with a factorial function. The
QUADRUPOLE case was missing and this was done by the default option. I also believe the default case should handle the generic case with a factorial division, but maybe I missed something.
Also I don't understand the
DIPOLE case, is this formula correct?