- 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

Move helper functions `_libelf_ar_get_{name,number,string}()` and
`_libelf_ar_open()` to a new compilation unit "libelf_ar_util.c"
to break the circular dependency between "elf_memory.o" and
"libelf_ar.o".

Obtained from: elftoolchain
MFC after: 1 month

Bug fixes to ar(1) archive handling:
- Correctly retrieve the initial (special) members of an archive after
an archive descriptor is rewound using elf_rand(SARMAG).
- Do not strip trailing white space from the 'raw' names retrieved
using elf_getarhdr().

Reported by: "Hyo geol, Lee" <hyogeollee at gmail dot com>

Use strncpy() instead of strlcpy() when copying members of
a `struct ar_hdr'. These members do not use NUL-termination
while strlcpy() expects its source buffer to be NUL-terminated.

MFP4: Add an implementation of the ELF(3) and GELF(3) API set.

Bump __FreeBSD_version.

Reviewed by: jb