OSPF: Send direct acknowledgements as unicast

Direct acknowledgements should be send as unicast to a corresponding
neighbor. Only delayed acks should be send as multicast to all/designated
routers.
32 jobs from master in 3 minutes and 42 seconds (queued for 11 seconds)
Status Job ID Name Coverage
  Image
passed #228542
dind allowed to fail
docker_centos-6-amd64

00:00:25

passed #228543
dind allowed to fail
docker_centos-7-amd64

00:00:25

passed #228532
dind allowed to fail
docker_debian-7-amd64

00:00:26

passed #228536
dind allowed to fail
docker_debian-7-i386

00:00:28

passed #228533
dind allowed to fail
docker_debian-8-amd64

00:00:27

passed #228537
dind allowed to fail
docker_debian-8-i386

00:00:30

passed #228534
dind allowed to fail
docker_debian-9-amd64

00:00:27

passed #228538
dind allowed to fail
docker_debian-9-i386

00:00:30

passed #228535
dind allowed to fail
docker_debian-testing-amd64

00:00:28

passed #228539
dind allowed to fail
docker_debian-testing-i386

00:00:30

passed #228540
dind allowed to fail
docker_fedora-25-amd64

00:00:29

passed #228541
dind allowed to fail
docker_fedora-26-amd64

00:00:32

passed #228544
dind allowed to fail
docker_opensuse-42_3-amd64

00:00:26

passed #228545
dind allowed to fail
docker_ubuntu-14_04-amd64

00:00:26

passed #228546
dind allowed to fail
docker_ubuntu-16_04-amd64

00:00:27

 
  Build
passed #228553
docker linux amd64
build-centos-6-amd64

00:01:01

passed #228554
docker linux amd64
build-centos-7-amd64

00:01:04

passed #228547
docker linux amd64
build-debian-7-amd64

00:01:45

passed #228558
docker linux amd64
build-debian-7-i386

00:01:03

passed #228548
docker linux amd64
build-debian-8-amd64

00:01:48

passed #228559
docker linux amd64
build-debian-8-i386

00:00:49

passed #228549
docker linux amd64
build-debian-9-amd64

00:01:04

passed #228560
docker linux amd64
build-debian-9-i386

00:00:50

passed #228550
docker linux amd64
build-debian-testing-amd64

00:01:05

passed #228561
docker linux amd64
build-debian-testing-i386

00:00:51

passed #228551
docker linux amd64
build-fedora-25-amd64

00:01:03

passed #228552
docker linux amd64
build-fedora-26-amd64

00:01:03

passed #228562
freebsd amd64
build-freebsd-11-amd64

00:02:11

passed #228563
freebsd i386
build-freebsd-11-i386

00:02:06

passed #228555
docker linux amd64
build-opensuse-42_3-amd64

00:01:02

passed #228556
docker linux amd64
build-ubuntu-14_04-amd64

00:01:02

passed #228557
docker linux amd64
build-ubuntu-16_04-amd64

00:01:04