BUG-954: Add support for Neutron port/network delete events for OF1.3

This commit will enable support for Neutron port delete and network delete events.
It will also enable flow cleanup and tunnel port delete for ovsdb using OF 1.3

(cherry picked from commit a16a1d44d3c16f92269fe56ebbe70389bec5258e)

Signed-off-by: Madhu Venugopal <mavenugo@gmail.com>
Change-Id: Ic848125d21abc44c796ef2b1675cca9e50630f76
Merge "BUG-954: Add support for Neutron port/network delete events for OF1.3" into stable/hydrogen