ipv6: wait for addresses to become usable (bnc#882259)

Added a temporary applying lease state, which is used while
applying a new granted lease to the system.

When a granted ipv6 lease arrives and the addresses are set,
we've to wait unti the kernel verifyed them for duplicates
and removes the tentative flag before we continue to apply
the rest of the lease and finally inform the client about.

When the kernel detects duplicates, the state changes either
to failed and we do not set further settings or to requesting
state for dhcpv6 leases as it automatically declines.
Merge pull request #382 from mtomaschewski/ipv6-tentative-1

ipv6: wait for addresses to become usable (bnc#882259)
fixed to consider temporary applying lease state
man: ifcfg-tunnel updates

Document support in wicked for sit, ipip and gre tunnels.
samples: xml config nodes for sit ipip and gre tunnels
Merge pull request #384 from kmroz/tunnel-doc-update

man: ifcfg-tunnel updates
Merge pull request #385 from kmroz/tunnel-samples

samples: xml config nodes for sit ipip and gre tunnels
ifevent: increase netlink socket recv buffer size

We saw that when setting up multiple bondings, our netlink socket receive
queue filled up before we could process it, generating the following:

netlink receive error: No buffer space available

and preventing the interfaces from being configured properly. Increasing
the receive buffer size on the netlink socket fixes this.
Merge pull request #386 from kmroz/nl-bufsize

ifevent: increase netlink socket recv buffer size
ipv6: removed duplicate check in address wait
Make debug msg about fsm timeout more obvious

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Adjust comment in ni_timer_get_time about the need for wallclock time

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Use generic buffer functions to manage dhcp4 msgbuffer

Signed-off-by: Olaf Hering <olaf@aepfle.de>
make ni_capture_retransmit static

Signed-off-by: Olaf Hering <olaf@aepfle.de>
make ni_dhcp4_fsm_set_timeout_msec static

Signed-off-by: Olaf Hering <olaf@aepfle.de>
make ni_dhcp4_fsm_set_timeout static

Signed-off-by: Olaf Hering <olaf@aepfle.de>
make __ni_dhcp4_fsm_discover static

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Remove ni_dhcp4_fsm_request prototype

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Remove ni_dhcp4_fsm_renewal prototype

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Remove ni_dhcp4_fsm_reboot prototype

Signed-off-by: Olaf Hering <olaf@aepfle.de>