Clarify the step in image service install guide

When follows the instructions at "Install the Image Service in
OpenStack Installation Guide for Ubuntu 12.04 (LTS)  - havana".

In step 8, we have to add options to filter:authtoken section.
It is not clear though in glance-api-paste.ini what the contents
of the section should be, since it contains the option:
delay_auth_decision = true

Add some information in step 8 so it is not confusing any more.

Change-Id: Ib29c2138b115720e72bee5a13066c79158e188f7
backport: havana
Closes-Bug: #1255552
add data network to Network connectivity for physical hosts

Change-Id: If99f5c3aa64b2d1c92ea4836c6a057cf08567ffb
Closes-Bug: #1252574
Merge "Clarify the step in image service install guide"
Add openstack-doc-tools to list of open reviews

Change-Id: Ia53275478c041e97aebec9ef2b2ef7c16784d453
Merge "add data network to Network connectivity for physical hosts"
Updated quota documentation. Added a word that was necessary at the end of the sentence.

Change-Id: I878820c2f0b32a2b6a2f19839dc0de9554e38786
Merge "Add openstack-doc-tools to list of open reviews"