Get instance networking information from Neutron

project/instances, admin/instances and the instance details page
all get networking information from Nova. However, with Neutron
enabled, floating IP associations are done direcly with Neutron,
meaning that Nova's DB will fall out of sync and thus the GUI
won't reflect successful floating IP associations until Nova
polls Neutron again and updates its DB. The polling can take
up to several minutes to complete for consecutive floating IP
operations.

The solution is to update instances' networking information from
Neutron immediately after the call to list Nova instances.

Closes-Bug: #1265032
Change-Id: I0382fa9a4a9fff21e7b4d05cd3b76783f826735f
Merge "Get instance networking information from Neutron"