BGP: Long-lived graceful restart enhancements

When use of LLGR is negotiated, handle hold timeout by LLGR instead of by
hard restart. Allow to configure whether BFD session down event should be
handled by GR/LLGR or by hard restart.
49 jobs for master in 10 minutes and 26 seconds (queued for 14 seconds)
Status Job ID Name Coverage
  Image
passed #151864
dind allowed to fail
docker_centos-6-amd64

00:01:34

passed #151865
dind allowed to fail
docker_centos-7-amd64

00:01:03

passed #151854
dind allowed to fail
docker_debian-7-amd64

00:00:55

passed #151858
dind allowed to fail
docker_debian-7-i386

00:01:01

passed #151855
dind allowed to fail
docker_debian-8-amd64

00:01:24

passed #151859
dind allowed to fail
docker_debian-8-i386

00:01:45

passed #151856
dind allowed to fail
docker_debian-9-amd64

00:01:06

passed #151860
dind allowed to fail
docker_debian-9-i386

00:01:05

passed #151857
dind allowed to fail
docker_debian-testing-amd64

00:01:13

passed #151861
dind allowed to fail
docker_debian-testing-i386

00:01:10

passed #151862
dind allowed to fail
docker_fedora-25-amd64

00:02:28

passed #151863
dind allowed to fail
docker_fedora-26-amd64

00:02:41

passed #151866
dind allowed to fail
docker_opensuse-42_3-amd64

00:02:11

passed #151867
dind allowed to fail
docker_ubuntu-14_04-amd64

00:01:07

passed #151868
dind allowed to fail
docker_ubuntu-16_04-amd64

00:01:04

 
  Build
passed #151881
docker linux amd64
build-centos-6-amd64

00:02:19

passed #151882
docker linux amd64
build-centos-6-amd64-v6

00:02:22

passed #151883
docker linux amd64
build-centos-7-amd64

00:02:21

passed #151884
docker linux amd64
build-centos-7-amd64-v6

00:01:59

passed #151869
docker linux amd64
build-debian-7-amd64

00:02:08

passed #151873
docker linux amd64
build-debian-7-amd64-v6

00:02:27

passed #151891
docker linux amd64
build-debian-7-i386

00:01:03

passed #151892
docker linux amd64
build-debian-7-i386-v6

00:00:55

passed #151870
docker linux amd64
build-debian-8-amd64

00:02:28

passed #151874
docker linux amd64
build-debian-8-amd64-v6

00:02:28

passed #151893
docker linux amd64
build-debian-8-i386

00:00:56

passed #151894
docker linux amd64
build-debian-8-i386-v6

00:00:58

passed #151871
docker linux amd64
build-debian-9-amd64

00:02:32

passed #151875
docker linux amd64
build-debian-9-amd64-v6

00:02:39

passed #151895
docker linux amd64
build-debian-9-i386

00:00:56

passed #151896
docker linux amd64
build-debian-9-i386-v6

00:00:58

passed #151872
docker linux amd64
build-debian-testing-amd64

00:02:27

passed #151876
docker linux amd64
build-debian-testing-amd64-v6

00:02:39

passed #151897
docker linux amd64
build-debian-testing-i386

00:00:55

passed #151898
docker linux amd64
build-debian-testing-i386-v6

00:00:57

passed #151877
docker linux amd64
build-fedora-25-amd64

00:02:39

passed #151878
docker linux amd64
build-fedora-25-amd64-v6

00:02:26

passed #151879
docker linux amd64
build-fedora-26-amd64

00:01:58

passed #151880
docker linux amd64
build-fedora-26-amd64-v6

00:02:31

passed #151899
freebsd amd64
build-freebsd-11-amd64

00:05:20

passed #151900
freebsd amd64
build-freebsd-11-amd64-v6

00:05:06

passed #151901
freebsd i386
build-freebsd-11-i386

00:05:24

passed #151902
freebsd i386
build-freebsd-i386-v6

00:05:23

passed #151885
docker linux amd64
build-opensuse-42_3-amd64

00:02:21

passed #151886
docker linux amd64
build-opensuse-42_3-amd64-v6

00:02:26

passed #151887
docker linux amd64
build-ubuntu-14_04-amd64

00:02:31

passed #151888
docker linux amd64
build-ubuntu-14_04-amd64-v6

00:02:27

passed #151889
docker linux amd64
build-ubuntu-16_04-amd64

00:01:06

passed #151890
docker linux amd64
build-ubuntu-16_04-amd64-v6

00:00:58