fixup! Rework option parser to support ‘--’ as escape sequence

I saw the discussion on the latex issue and I thought I should look into the problem with the dialog commands. This fixes the issue for `"$DIALOG" nib --list`, but  `"$DIALOG" nib --wait  «token»` works for me before this change (unless you were referring to when no argument was passed to `--wait` and it fail to give an error  (i.e., `$DIALOG" nib --wait`).