Update links for vanilla images in doc

* Update links for vanilla 1 plugin images
* Add links to Hadoop 2 images

Change-Id: I71cf69d424c7b53082d0980479967a8f4128a167
(cherry picked from commit 4ff36b320eb2cdf7146197913f41efbc917c5e1b)
Minor fixes to Sahara UI Installation Guide

 * removed item #7 - it is not needed and is misleading
 * rephrased clarification for AUTO_ASSIGNMENT_ENABLED
 * renamed 'Nova Network' to 'Nova-Network' - seems like the later is
   the only name which is used

Partial-Implements: blueprint update-docs-icehouse
Change-Id: Ibb177820da8d44e1f70a8fd7273dadd57e81ad1e
(cherry picked from commit 253ab59a3bfb0066b46935edc18cb252f962877b)
Doc's update for integration tests

* Description of tests was changed and complemented;
* List of tests to each plugin and its version was added.

Change-Id: I8de087d745cb83dfc6da67d1bc5036cacd1b6b80
(cherry picked from commit 3a00dd05e3a1df5ecfc3e0423c439db4d4153eda)