Update the URL to the MIST files that were moved

Allow minimint to work in Windows.

This is a refactoring release with some corner cases fixed.

This release of minimint presents significant speedups when evaluating isochrones on a large number of stars. Speed up is expected to be at least a factor of 10.

This release provides a workaround of the astropy bug astropy/astropy#11627 which can manifest itself as VerifyError: Long card images must have CONTINUE cards after the first card. message when doing 'download_and_prepare'

• Speedups
• Fix of the problem with isochones not interpolating at the edge of the grid (i.e. feh>0.25)
• The behaviour of getMaxMass changed a bit for some weird isochrones

Singificant speed up of the package and some additional functions