Add linuxbridge mechanism support for ML2 plugin

Add support for the Linux Bridge mechanism. It includes support
for VXLAN tunneling and L2 population.

Change-Id: I0faca3d4603c6eacbbaa61adef7b742b3a262641
Add ability to configure dhcp_agent_notification

Add a new dhcp_agent_notification parameter to allow its configuration.

Installation without any DHCP agents should have this option disabled
to avoid these kinds of error messages in Neutron logs:

- No more DHCP agents
- Unable to schedule network XXX: no agents available;
  will retry on subsequent port creation events.
- Will not send event port_create_end for network XXX:
  no agent available.

Change-Id: I42a5a045b777e42e5c99cea16a0fbc6ed145d73b
for OVS agent, fix dependency on service

Previously, the declaration for vs_bridge required the service, but if
the service is not enabled it's not declared.  This moves the dependency
inside an if.  See bug #1298146 for the background.

Change-Id: Ic51efb16d4ba0a971178ff648f963c61b2e9fdde
Closes-Bug: #1337733
Install neutron-plugin-ml2 package on Ubuntu

While there is no dedicated package for neutron-plugin-ml2 on Debian,
there is one on Ubuntu operating systems.

We should install it when ML2 core plugin is enabled.

Closes-bug: #1337988
Change-Id: I8ee2bca21cc3f32c017529b55c92a50094aa25d5
agent/lbaas: fix HAproxy package relationship

This patch fix this case:
- manage_haproxy_package is set to false
- puppetlabs-haproxy is not running
- we still want Neutron LBaaS working on the node
- we don't want at all the package managed by Puppet

Only set the dependency if the package is defined in the catalog.

Closes-bug #1340999
Signed-off-by: Emilien Macchi <emilien.macchi@enovance.com>
Change-Id: Iee2211db8add4dfafba70706d69d1092339c6206
Make Nova_admin_tenant_id_setter notify neutron-server.

Add notification to ensure that changes in Nova_admin_tenant_id_setter
 will result with neutron-server restarting. This is necessary, otherwise
 it is possible for neutron.conf DEFAULT/nova_admin_tenant_id to not be set
 which will result in odd looking auth failures and cause instances to fail
 booting

Change-Id: Idbb2fe9ce63985e4236e41a642ef1b783bec3753
Closes-bug: #1343009