Ensure that L3 managed port have status ACTIVE

Some plugins may set the port status as DOWN when it is created. This was not
updated when the port was actually up. This patch ensures that gateway and
router ports that are created will be set as ACTIVE when they are actually
up and running.

Ports that are attached to additional bridges in the OVS will only update the
port status as ACTIVE. There will be no tags set on the specific ports as this
will break the existing functionality.

Fixes bug 1192883

(cherry picked from commit d88ea97228ec8bb38f071c3969fdbb3abf6ab575)

Conflicts:

	quantum/tests/unit/openvswitch/test_ovs_quantum_agent.py
	quantum/agent/linux/ovs_lib.py
	quantum/plugins/openvswitch/agent/ovs_quantum_agent.py
	quantum/tests/unit/openvswitch/test_ovs_tunnel.py

Change-Id: I9993f56963ac704f0f345102d2e8b2d99dd9ad9e
Merge "Ensure that L3 managed port have status ACTIVE" into stable/grizzly