Adds the new IBM SDN-VE plugin

It adds a new plugin for SDN-VE, the IBM SDN
controller. The plugin supports the core API
and the port binding and L3 extensions.

Implements: blueprint ibm-sdn-ve-plugin
DocImpact

Change-Id: I92619a95bca2ae0c37e7fdd39da30119b43d1ad6
Merge "Adds the new IBM SDN-VE plugin"