- 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

According to shared memory man pages, advice including <sys/types.h>
instead of <sys/param.h>

The NetBSD Foundation has granted permission to remove clause 3 and 4 from
their software.

Obtained from: NetBSD

Fix message size tests for msgsnd(3) and msgrcv(3). msgsz is the length of
actual message and it should not include size of message type.

Add regression tests for sysvipc.

Submitted by: Hiten Pandya <hiten@uk.FreeBSD.org>
Obtained from: NetBSD