dhcrelay has the ability to monitor interfaces for requests
in a single direction only rather than listening to all
interfaces for requests.

Doing this allows one to suppress the duplication of having
the relay forward requests from the same network that the
DHCP server is on.

Signed-off-by: Brian J. Murrell <brian@interlinx.bc.ca>

Version bumped to 4.3.5.  Separated out compile/install steps since
compiling with $DESTDIR yields bogus results. Removed rfc-3527 patch
as something similar (better) is now upstream (well, more complete
error checking anyway). Change relay scripts from '-l ifname' to
'-U ifname' to correspond to upstream changes.

Signed-off-by: Philip Prindeville <philipp@redfish-solutions.com>

Signed-off-by: Antony Antony <antony@phenome.org>