Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Fix regression introduced with NFSv4 ACL support - make acl_to_text(3)
and acl_calc_mask(3) return error instead of crashing when acl passed
to them is NULL.

Submitted by: markus
Reviewed by: rwatson
MFC after: 3 days

Add NFSv4 ACL support to libc.

This adds the following functions to the acl(3) API: acl_add_flag_np,
acl_clear_flags_np, acl_create_entry_np, acl_delete_entry_np,
acl_delete_flag_np, acl_get_extended_np, acl_get_flag_np, acl_get_flagset_np,
acl_set_extended_np, acl_set_flagset_np, acl_to_text_np, acl_is_trivial_np,
acl_strip_np, acl_get_brand_np. Most of them are similar to what Darwin
does. There are no backward-incompatible changes.

Approved by: rwatson@

Replace the non-standard disclaimer with the standard one from /COPYRIGHT

Approved by: jedgar@

Fix the style of the SCM ID's.
I believe have made all of libc .c's as consistent as possible.

o style and consistency fixes:
- if (!var) -> if (var == NULL)
- return val; -> return (val);
o update copyright

o Separate acl_t into internal and external representations as
required by POSIX.1e. This maintains the current 'struct acl'
in the kernel while providing the generic external acl_t
interface required to complete the ACL editing library.
o Add the acl_get_entry() function.
o Convert the existing ACL utilities, getfacl and setfacl, to
fully make use of the ACL editing library.

Obtained from: TrustedBSD Project

Prepare for the inclusion of libposix1e into libc: retire the old
Makefile, add Makefile.inc needed for libc build; add
#include "namespace.h"/#include "un-namespace.h" pairs around the
includes of sys/acl.h and sys/capability.h, and an additional underscore
in front of the functions that will be overridden in libc_r.

Approved by: rwatson
Obtained from: TrustedBSD Project

Add the following POSIX 1003.1e functions and man pages:
o acl_calc_mask(): calculates the ACL mask entry associated with
the given ACL.
o acl_delete_entry(): remove a specified ACL entry from the given
ACL.

Approved by: rwatson