[Patch] Use dashes, not hyphens in manpage
In the manpage, plain - characters are used, which are rendered as (non-ASCII) hyphens by groff. This is ok for e.g. "read-only", but for e.g. "--grf" dashes are needed to make copy-pasting work.
I've attached a patch which fixes this. Technically, it seems that inside the .Fl macro, this is not necessary, but it doesn't hurt either (and is good for consistency).
This fixes a lintian warning in Debian: https://lintian.debian.org/tags/hyphen-used-as-minus-sign.html