Merge branch 'devel-2.3'

* devel-2.3:
  locking: Clarify message for removed locks
  Bump version for 2.3.1~rc1 release
  impexpd: Disable OpenSSL compression in socat if possible
  Bump version for 2.3.0

Conflicts:
	NEWS: Trivial

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>