man: list options one per line

man: list options one per line

Somewhat inspired by my selfish use of VIM as man pager. Namely, when
there are multiple options on the same line, only the first one gets
properly rendered.

A good bonus point is that very long instances, like modinfo's legacy
"--author, --description ..." look a bit neater now.

With this is also more consistently handle short/long options which take
an argument.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>