Advanced Services documentation

Adds the beginnings of documentation for the Firewall as a Service,
Loadbalancer as a Service, and VPN as a Service.

Part of blueprint developer-documentation

Change-Id: I5e46df2dc4f87f961490ee75791a7e825ea94e1e
Set ns_name in RouterInfo as attribute

Closes-Bug: #1302007
Change-Id: I02a9b92eea06010569d3d9c5a987e69f89b23be5
ML2: ODL driver sets port status

The OpenDaylight mechanism driver does not depend on an L2 agent to
plug the port. Now that nova waits for notification that the port
status is ACTIVE, the ML2 driver API is extended so that the mechanism
driver that binds a port can optionally set the port status, and the
OpenDaylight mechanism driver uses this to set the port status to
ACTIVE.

Closes-Bug: 1301449
Change-Id: I171c405f36b4f2354d9585e8ae3dfa50ddaa9a7e
Merge "Set ns_name in RouterInfo as attribute"
Merge "Advanced Services documentation"