- 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

Add section .note.GNU-stack for assembly files used by 386 and amd64.

Add missing END() macros, as per rev 184547 for amd64. The lack of these
is mostly harmless, but it does upset some of valgrind's functionality.

MFp4: Pentium/Athlon-optimised implementation of wcslen().