Restore config check in ni_dhcp4_fsm_release

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Retry DHCP4 rebind until lease_time is reached

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Restart DHCP4 fsm in case of timeout in reboot state

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Print DHCP4 state name in case DHCLIENT_WAIT_AT_BOOT is reached

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Merge pull request #397 from olafhering/olh-misc

DHCP4 rebind/reboot fixes