ifupdown2 now tries to monitor the dhclient call to see if an ip address was
successfully assigned on the requested device. The number of retry can be
customized using the "dhclient_retry_on_failure" policy variable (which defaults to 0)
This commit also add debugging capabilities by automatically enabling sysloging when
configuring dhcp at boot (with PERFMODE option).
Signed-off-by: Julien Fortin <julien@cumulusnetworks.com>
