Big Switch: Bind IVS ports in ML2 driver

Add support to bind IVS ports in the Big Switch ML2
mechanism driver. The backend controller will be checked
to determine if a host is connected using the Indigo vswitch.
If so, the mechanism driver will mark it as bound since
it will be provisioned by the backend controller.

Implements: blueprint bsn-ml2-bind-ivs
Change-Id: Ic481fc31c8c123899fddf8185c32f127dff53b7a
Revert "Skip functional l3 agent test"

This reverts commit 0918ce91e5af5100ee3a4fcd6861741c4f00ac41. The
specified commit skipped a test which caused non-deterministic gate
failures, but the actual reason for the failures was found and fixed
so the skip is no longer needed.

Related-bug: #1358206
Related-bug: #1364171
Change-Id: I9b0d9ad9ad8b62ee92877fc0a6db0323604433ac
Avoid testing code duplication which introduced testing bugs

SecurityGroupAgentEnhancedRpcTestCase duplicated code in
SecurityGroupAgentRpcTestCase setUp, also
TestSecurityGroupAgentEnhancedRpcWithIptables duplicated
code from TestSecurityGroupAgentWithIptables setUp()
introducing bugs by improper initialization, like a missing
    self.iptables.use_ipv6 = True
which in combination with tests.unit.test_ipv6.TestIsEnabled
produced inconsistent testing results.

Change-Id: Ic0b596b6fe1d8273df197e9426abad818832c00a
Closes-bug: #1365829
Fixes formatting for debug output in neutron/agent/l3_agent.py

The %s format type was missing.

Change-Id: I4efba513f7b0a6e4a21908bf0b05407e74b524c7
Closes-bug: #1366105
Stop tracking connections in DVR FIP Namespace

For DVR, connections to external network using floating IPs do not
need to be tracked in FIP namespace because they are being
already tracked in router namespace.
This fix adds iptable rules to not track connections.

Change-Id: I378039e311763d114860cb70ded7349d6580855a
Closes-bug: #1360395
Merge "Fixes formatting for debug output in neutron/agent/l3_agent.py"
Merge "Revert "Skip functional l3 agent test""
Merge "Avoid testing code duplication which introduced testing bugs"
Merge "Stop tracking connections in DVR FIP Namespace"
Merge "Big Switch: Bind IVS ports in ML2 driver"