MFC r318968:
Add missing usage and getopt(3) options
- Add the missing option 'n' to the getopt(3) string
- Add the missing options 'libxo' and 'N' to the usage message
- Add the missing options 'M' and 'N' to the man-page
Submitted by: Keegan Drake H.P. <kdrakehp@zoho.com>
Differential Revision: https://reviews.freebsd.org/D10915
Approved by: re (gjb)