This file apparently relies on the fact that `sys/wait.h` _may_ include
symbols from `signal.h`, but as we don't have that (and it isn't a
requirement), let's just add the include for `signal.h`.
We may need entries with spaces in makeopts, installopts, and
configopts, and at that point we should also convert depends and
auth_opts to avoid confusion.
- Replaced /Root with
- Improved documentation.
- Removed a few typos.
- Replaced with
- Added brackets in some cases.
Most of the changes were reviewed and applied manually.
