Overhaul dhcpcd for chrome os use

dhcpcd-hooks/50-dhcpcd-compat

-# Compat enter hook shim for older dhcpcd versions
-
-IPADDR=$new_ip_address
-INTERFACE=$interface
-NETMASK=$new_subnet_mask
-BROADCAST=$new_broadcast_address
-NETWORK=$new_network_number
-DHCPSID=$new_dhcp_server_identifier
-GATEWAYS=$new_routers
-DNSSERVERS=$new_domain_name_servers
-DNSDOMAIN=$new_domain_name
-DNSSEARCH=$new_domain_search
-NISDOMAIN=$new_nis_domain
-NISSERVERS=$new_nis_servers
-NTPSERVERS=$new_ntp_servers
-
-GATEWAY=
-for x in $new_routers; do
-        GATEWAY="$GATEWAY${GATEWAY:+,}$x"
-done
-DNS=
-for x in $new_domain_name_servers; do
-        DNS="$DNS${DNS:+,}$x"
-done
-
-x="down"
-case "$reason" in
-RENEW) x="up";;
-BOUND|INFORM|REBIND|REBOOT|TEST|TIMEOUT|IPV4LL) x="new";;
-esac
-
-if [ "$reason" != "down" ]; then
-        rm -f /var/lib/dhcpcd-"$INTERFACE".info
-        for x in IPADDR INTERFACE NETMASK BROADCAST NETWORK DHCPSID GATEWAYS \
-                DNSSERVERS DNSDOMAIN DNSSEARCH NISDOMAIN NISSERVERS \
-                NTPSERVERS GATEWAY DNS; do
-                eval echo "$x=\'\$$x\'" >> /var/lib/dhcpcd-"$INTERFACE".info
-        done
-fi
-
-set -- /var/lib/dhcpcd-"$INTERFACE".info "$x"