Updated openstack/openstack
Project: openstack/neutron  6983940b6ef272746e9e605d6df03854166e6e76

Support for extensions in ML2

The current ML2 plugin supports only extensions defined in the plugin and it
does not support any extensions in the mechanism drivers. The changes in this
commit allows mechanism drivers to define new extensions.

Change-Id: I28da19fabf6de2e9f0d687f875aaaa24c8bbc4f0
Implements: blueprint extensions-in-ml2