dhcp: nettools: read/write lease files

Use the same format of systemd-netword, so that we will be compatible
with the leases created/read by the current "internal" plugin.
Note that actually only the leased address is processed when reading a
lease file, so no need to save more than the ip address when saving the
lease.
19 jobs for fg/nettools_persist_lease in 104 minutes and 9 seconds (queued for 22 seconds)
latest
Status Job ID Name Coverage
  Test
passed #549164
allowed to fail
checkpatch

00:01:42

manual #549169
allowed to fail manual
t_centos:7.5.1804
passed #549170
t_centos:7.6.1810

00:25:36

passed #549176
t_debian:10

00:19:37

passed #549175
t_debian:9

00:20:39

passed #549178
t_debian:sid

00:17:39

manual #549177
allowed to fail manual
t_debian:testing
passed #549165
t_fedora:28

00:31:49

passed #567890
t_fedora:29

00:36:41

passed #567891
t_fedora:30

00:30:01

manual #549168
allowed to fail manual
t_fedora:rawhide
passed #549171
t_ubuntu:16.04

00:19:32

passed #549172
t_ubuntu:18.04

00:13:36

manual #549174
allowed to fail manual
t_ubuntu:devel
manual #549173
allowed to fail manual
t_ubuntu:rolling
failed #549166
t_fedora:29

00:02:16

failed #549167
t_fedora:30

00:00:54

 
  External
failed https://desktopqe-jenkins.rhev-ci-vms.eng.rdu2.redhat.com/job/beaker-NetworkManager-gitlab-trigger-code-upstream/637/

failed https://desktopqe-jenkins.rhev-ci-vms.eng.rdu2.redhat.com/job/beaker-NetworkManager-gitlab-trigger-code-upstream/637/

07:50:07