--unamed-opts

I'm not sure if --unamed-opts is having the intended behaviour.

It is defined as:
--unamed-opts
the program will accept also options without a name, which, in most
case, means that we can pass many file names to the program

But I tested that currently if it is not set, but the user still
passes unamed options, it does not cause any error when parsing, it
just doesn't process them.

So I think it should fail the parsing and throw a message that
unexpected unamed options were found, or that this description is
changed to something that makes that clear:

"the program will parse also options without a name, which, in most
case, means that we can pass many file names to the program. If not
set options without a name are ignored"

Nuno