Add support for router scheduling in Cisco N1kv Plugin

Added functionality for router and network scheduling
in Cisco N1kv Plugin.

Change-Id: I1a8d27670d10ca26fb62a8d02230a1aaf3e7bbca
Closes-Bug: #1286412
Remove duplicated tests for check_ovs_vxlan_version

test_ovs_lib, test_ovs_neutron_agent and test_ofa_neutron_agent
have duplicated same unit tests for check_ovs_vxlan_version.
This commits removes tests from ovs/ofa_neutron_agent.

Change-Id: Ia028a4afc1c8154f895187c979d23b626ab4ae3a
Closes-Bug: #1301337
Clean out namespaces even if we don't delete namespaces

Even when we don't enable namespace deletion, we still want to run the
code that cleans out the namespaces so that the devices get unplugged,
etc.  Otherwise, routers deleted while the agent is down will continue
to operate as if they were never deleted.

The trade-off to consider here is that if there are many stale
namespaces this will slow down the restart of the L3 agent.  The best
option is to get namespace deletion working correctly.  However, where
that has not been worked out yet, this patch provides the cleaning
service for deleted routers.

Change-Id: Ic7b4608a23c4d9530f521d5faff3f8526200b92e
Closes-Bug: #1301042
Related-Bug: #1052535
OFAgent: Avoid re-wiring ports unnecessarily

Port the following patch to OFAgent.
commit: a9050757d94009c68f06c9f374de33eefbf06aa9
https://review.openstack.org/#/c/63558/

Partial-Bug: 1293265

Change-Id: I35d58bad104b01136c2502c933475ac85a3752a5
Set the log level to debug for loading extensions

Setting the log level to debug instead of info
for load extension file.

Change-Id: Ia2322a5d62381f15b4bf4e0bb7120813be985786
BSN: Remove module-level ref to httplib method

Removes a module-level variable that was just a
pointer to the httplib.HTTPConnection class. It's
purpose was to give mock.patch a target that wouldn't
affect other code using the httplib.HTTPConnection
library. However, it is unnecessary now that the
root cause of the original patches not being stopped
by mock.patch.stopall was fixed in bug 1303605 (change
Ia5b374c5f8d3a7905d915de4f1f8d4f3a6f0e58d).

Closes-Bug: #1304558
Change-Id: Idf814b075a80245bb9751466c2b58d719a1b81f3
Revert "Hide ipv6 subnet API attributes"

This reverts commit d739486a3f70cb83f8730cf7201a8b8ccf4b4c70.

Change-Id: I27352ba5442da8c69c2d1ab6d5e333e95dc5ebf7
Merge "Add support for router scheduling in Cisco N1kv Plugin"
Merge "BSN: Remove module-level ref to httplib method"
Merge "Clean out namespaces even if we don't delete namespaces"
Merge "Remove duplicated tests for check_ovs_vxlan_version"
Merge "Set the log level to debug for loading extensions"
Merge "Revert "Hide ipv6 subnet API attributes""
Merge "OFAgent: Avoid re-wiring ports unnecessarily"