Fix to enable L2pop to serve DVR

This change fixes the information used by the L2pop
driver to populate l2pop rules that enables DVR to
route packets across compute servers that have
tenant VMs that belong to different networks.
It also fixes the case where VMs were not able to
obtain IP Addresses when such VMs are on DVR
hosted subnets.

Change-Id: Ib630e57c186da60eb15f9ffa6b1b0bfa74f48caa
Closes-Bug: #1350485
Closes-Bug: #1352857
DeferredBridge to allow add_tunnel_port passthru

The DeferredBridge should allow add_tunnel_port
method as passthrough in addition to add_port
and delete_port. L2Pop uses add_tunnel_port to
dynamically establish tunnel endpoints on cloud
nodes.

Closes-Bug: #1353885

Change-Id: I2e6d82ee79814e500604f4951e7d89eab662047a
Merge "Fix to enable L2pop to serve DVR"