Update the network info when using quantum.

The network info cache in quantum was not updated with floating ips.
Also it wasn't updated properly updating the network info cache
during some operations that changed it. This adds floating ips and
updates the cache properly.

Fixes bug 1108975

Change-Id: I9e9c211d014f9671d724cded1fb9a74313c458b6
Merge "Update the network info when using quantum."