science/mmg: Update 5.7.3 => 5.8.0, take maintainership
Changelogs:
- https://github.com/MmgTools/mmg/releases/tag/v5.8.0
- https://github.com/MmgTools/mmg/compare/v5.7.3...v5.8.0
- Add WWW for source code repository
- Clarify LICENSE and pkg-descr
- Pet portclippy(1) and portfmt(1)
- Bash is still needed for running some configure script - scripts/git_log_mmg.sh, so is patching it with shebangfix
Approved by: yuri@ (Mentor)
Differential Revision: https://reviews.freebsd.org/D53593