Fix IP addresses in Install Guide

This fixes a few wrong IP addresses in the Install Guide.

Explain also network setup in section_nova-compute.xml.

Change-Id: I5f644074266323ee5e10f9587686991266e72442
Closes-Bug: #1307188
Give IP address for Block Storage service node

Provide an IP address for the node so that it's clear in which network
the host should be.

Change-Id: I6439869dd69b0e0f2a50ec125ca0cd1f5c7e90cb
Partial-Bug: #1307185
Merge "Give IP address for Block Storage service node"
Merge "Fix IP addresses in Install Guide"