- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

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

Include a couple of headers to ensure consistency between the prototype and
the function definition.

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

Check if string is not NULL, not *string, before setting *string.

o Reflect repo-copy of extattr.[c3] from libutil to libc, moving
extattr namespace routines to the libc/posix1e directory. While
the extattr calls are not strictly POSIX.1e, POSIX.1e wasn't
strictly ever approved, so I think that's OK.

Obtained from: TrustedBSD Project

Add __FBSDID()s to libutil

o Rename "namespace" argument to "attrnamespace" as namespace is a C++
reserved word.

Submitted by: jkh
Obtained from: TrustedBSD Project

o To support new EA interface with explicit namespaces, introduce two
utility functions which convert between string namespace names and
numeric constants used by the interface. Right now, two namespaces
are supported, EXTATTR_NAMESPACE_SYSTEM ("system") and
EXTATTR_NAMESPACE_USER ("user"). These functions are used by
various userland EA utilities, rather than hard coding the routines
all over the place.

Obtained from: TrustedBSD Project