itsmoosh/MoonMag: Saving Xid and parallel processing toggles

New in this version, lengthy calculations for evaluating mixing coefficients Xid have been circumvented by saving them to disk. They are reloaded by default, and for new combinations a file is generated locally. More may be added in future.

Also added are toggles for parallelization in induction moment calculation functions. This allows them to be put into other loops done in parallel.

All terminal outputs have been moved to commands from the logging module.