Add option to configure help width

[ShaneMurphy2]

When viewing the help output on a vertical monitor, almost all the help text wraps pretty terribly. It would be nice to be able to configure newlines between the help text and things like enum options.

So instead of this:

  -o, --option     <option>  - Some option help.                           (required, Values: "foo
", "bar")

I'm thinking this:

  -o, --option     <option>  - Some option help. 
                               (required, Values: "foo", "bar")

It seems like this is a result of the output formatter assuming a fixed terminal width.