- Fix UseMulticast.patch to not repeatedly parse dhcpd.conf for unicast
        option
    - Fix dhclient-script to set interface MTU only when it's greater than 576
        (#574629)
    - In dhclient-script:
    - use ip command options '-4' or '-6' as shortcuts for '-f[amily] inet'
        resp. '-f[amily] inet6'
    - do not use IP protocol family identifier with 'ip link'