* Add -i option to install the new dhcpd file into place, backing up
  the old version. Does not restart dhcpd though; that is left to
  someone else at the moment. May change later. Without -i, works as
  before, writing the new config file to stdout. Of course, must use
  the standard locking protocol to serialize when using -i, lest we
  end up with a garbled dhcpd.conf file.

* Add -t option to specify the template file. Changed default
  behaviour so that without any args, uses the template file in
  /usr/local/etc. Together with -i option, this moves the two
  hardwired paths to a single place (script).

* Changed how utiils/newnode script calls dhcpd_makeconf (call with
  just -i option to let dhcpd_makeconf handle all that icky stuff).

* Changed how install/boss-install script calls dhcpd_makeconf (call with
  just -i option to let dhcpd_makeconf handle all that icky stuff).

* Also change boss-install to use install target in dhcpd directory,
  to install the template file.