Similar to the chgrp(1)-audit:
1) Refactor manpage so it's actually fun to read
2) BUGFIX: Call (l)chown properly when the H-flag is specified
(only when depth > 0)
3) BUGFIX: Call (l)chown properly when the h-flag is specified
(only when depth = 0).
4) BUGFIX: Only recurse() in chgrp() when the initial chownf()
succeeds.
5) Style fixes, argv-basing.
6) Rename status to ret for consistency.
7) Add blank line before return.
- add .Os, it is mandatory.
- don't redeclare .Nm when it's not needed.
- fix some warnings (checked with mandoc -Tlint).
- remove some leftover old stuff.
