* step shared libc version to 12.20
* pick up move of com(4), lpt(4) headers from dev/isa to dev/ic
* remove imp.4 (Arpanet 1822) manpage.
For now, leave manpage references to syscalls that are still emulated
in libc dangling.
- Update libc, libg++, and libstdc++ shared library versions where
appropriate
- Move LKMs to base/mi (except union and compat_sunos, which are broken
and currently not part of the set lists)
- Add /usr/bin/fdformat to base/md.i386, from PR 3116
- Add /etc/fstab.sd to etc/md.i386, inspired by PR 3116