- 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

Drop all received data mbufs from a socket's queue if the MT_SONAME
mbuf is dropped, to preserve the invariant in the PR_ADDR case.

Add a regression test to detect this condition, but do not hook it
up to the build for now.

PR: kern/38495
Submitted by: James Juran
Reviewed by: sam, rwatson
Obtained from: NetBSD
MFC after: 2 weeks