- 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

Put my name as copyright owner of lib/libc/gen/dirfd.c added in r235647.

Requested by: kib@

Hide DIR definition by making it an opaque struct typedef.

Introduce dirfd() libc exported symbol replacing macro with same name,
preserve _dirfd() macro for internal use.

Replace dirp->dd_fd with dirfd() call. Avoid using dirfd as variable
name to prevent shadowing global symbol.

Sponsored by: Google Summer Of Code 2011