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)

Don't use pointer to 64 bit value (id_t) to point to 32 bit value (uid_t).

Found with: Coverity Prevent
CID: 7466, 7467
MFC after: 2 weeks

Don't forget to free the string in error case.

Found with: Coverity Prevent
CID: 6585

Make acl_to_text_np(3) not crash on long group or user names in NFSv4 ACLs.

PR: amd64/145091
MFC after: 2 weeks

Fix c194955 - somehow I managed all the new files, tripling their
contents.

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@