LBaaS: synchronize haproxy deploy/undeploy_instance methods

When creating/deleting lbaas objects at a high rate (like tempest api tests do)
deploy/undeploy_unstance methods of haproxy namespace driver
may be executed concurrently which leads to different conflicts with
network namespaces and interfaces created by the diver.

@synchronized decorator should be used in order to ensure that only one thread
will execute one of the methods at a time.

Closes-Bug: #1260692

Change-Id: Ibe86653c20c9a4e0b4e7b3b2cefbd445428b82da
L3 Agent can handle many external networks

With this patch a l3 agent can handle
any networks by setting the neutron
parameter external_network_bridge
and gateway_external_network_id to
empty.

Related-Bug: #1234750
Related-Bug: #1194350

Change-Id: Id260a239df23951da730513f40cda490002effc3
Make timeout for ovs-vsctl configurable

This patch adds a new configuration variable for the timeout on
ovs-vsctl commands, and sets the default timeout to 10 seconds.
This is aimed at allowing users to tune the agents in order to avoid
timeout errors on their deployments.

Change-Id: I73ea0d0de49a4b4a118bc2d68ad9c093ea122717
Closes-Bug: #1254520
Merge "Make timeout for ovs-vsctl configurable"
Merge "L3 Agent can handle many external networks"
Fix pip install failure due to missing nvp.ini file

It looks like sdist does not support symlinks, therefore
letting nvp.ini point to nsx.ini is not a good solution.
Since nvp.ini is going away, leave a copy for now, but
add a warning so that users are aware of the switch,
whilst preserving full backward-compatibility.

Closes-bug: #1266555

Change-Id: Id98c41145712583072a8e63a5de31ecc1074e420
Merge "LBaaS: synchronize haproxy deploy/undeploy_instance methods"
Merge branch 'master' of git://git.openstack.org/openstack/neutron into odl_ml2