Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

The 'acl_cnt' field is unsigned; no point in checking if it's >= 0.

Found with: Coverity Prevent
CID: 6192

The 'acl_cnt' field is unsigned; no point in checking if it's >= 0.

Found with: Coverity Prevent
CID: 6193

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@

Fix off by one error in acl_create_entry(3).

Reviewed by: rwatson@
MFC after: 2 weeks

Make 'struct acl' larger, as required to support NFSv4 ACLs. Provide
compatibility interfaces in both kernel and libc.

Reviewed by: rwatson

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

Add the remaining POSIX.1e ACL definitions:
ACL_UNDEFINED_TAG, ACL_UNDEFINED_ID, ACL_FIRST_ENTRY, ACL_NEXT_ENTRY

Reviewed by: rwatson
Obtained from: TrustedBSD Project

Revamp acl_create_entry() so it actually works.

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 ACL editing functions:
acl_add_perm, acl_clear_perms, acl_copy_entry, acl_create_entry,
acl_delete_perm, acl_get_permset, acl_get_qualifier, acl_get_tag_type,
acl_set_permset, acl_set_qualifier, acl_set_tag_type

This brings us within 4 functions of a full ACL editing library.

Reviewed by: rwatson