
Enhances openvswitch plugin to support flat networks and VLANs on multiple physical networks via the provider extension. Implements blueprint provider-networks. See http://wiki.openstack.org/ConfigureOpenvswitch for configuration and usage details. A devstack patch to support the updated openvswitch configuration variables is at https://review.openstack.org/#/c/11418/. Change-Id: Ic86b6f3b2e354c7d60bc2c330b334c23d349bc29