Remove richacl support

There's no support for richacl in Linux and based on information in the
links will never be. Remove all related files and support code.

References:
- https://wiki.samba.org/index.php/NFS4_ACL_overview#Linux
- https://lwn.net/Articles/661357/ (article, 2015)
- https://lwn.net/Articles/661078/ (patches, 2015)
- https://github.com/andreas-gruenbacher/richacl/
- http://www.bestbits.at/richacl/ (n/a anymore)

Signed-off-by: David Sterba <dsterba@suse.com>
Reviewed-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Zorro Lang <zlang@redhat.com>
Signed-off-by: Zorro Lang <zlang@kernel.org>
22 files changed