Quantum: under the hood details

Add a chapter in Network Admin guide that describes how the Open
vSwitch plugin and Linux bridging plugins configure the various
network devices on the compute and networking hosts.

All of the images and code are from Etsuji Nakai (Red Hat) from the
slides:

http://www.slideshare.net/enakai/how-quantum-configures-virtual-networks-under-the-hood

This content has been added to the docs with Etsuji's permission, and
he has been recorded as author of this commit.

Lorin added some supporting text and specified (guessed) at the config
file options.

Change-Id: Ie2ce069b025bde273c20c8324317af24ddd4d019
Add virt-edit example to Image Guide

Change-Id: I1b0081c8b6e16f56b2078075a635c5eddc7531d9
Remove floating CLI from compute admin

Remove the section on how to use floating IPs from compute admin,
add a link to the OpenStack Clients guide instead.

Change-Id: Ie870fa31ac9b5257333a3504c2f6fe136ebcde93
Merge "Add virt-edit example to Image Guide"
Merge "Quantum: under the hood details"
Merge "Remove floating CLI from compute admin"