SWMF/share library is out of date #78

The bundled share library is out of date and incompatible with GCC10.
In particular, the make_dir subroutine in share/Library/src/ModUtility.f90 sets an octal permission mask. This is no longer allowed under GCC10, but the routine has already been rewritten in the upstream repo (and actually has a different calling syntax).

The share folder should be updated to the latest version from SWMF.