attributes' for backward compatibility
Ticket: CM-1438
Reviewed By:
Testing Done: Tested ifupdown sanity and new functionality
support for:
- -i <interface file>
- template lookup path and move all template handling to a separate
module template.py
- new ifupdown2 config file /etc/network/ifupdown2/ifupdown2.conf
- bridge_waitport and bridge_maxwait
- moved addons.conf to /var/lib/ifupdownaddons/
