Switch to dhcpd.conf.d This commit adds dhcpd.conf.d as a directory for containing configuration file fragments. This permits the dhcpd instance to be configured almost entirely by the sg-dhcp role, but for additional assets such as a file containing MAC addresses to be 'dropped in'. A script is also provided in /usr/local/sbin/dhcpd-reconf which will reconfigure the dhcpd server and restart it.