Cleanup HA Guide

Cleanup HA Guide to better follow our XML conventions and practices:
* Change simpara to para. We do not use simpare in our guides.
* Remove <info> around titles, this is not really needed and not done in
  other guides.
* Change <xi:include href="./file.xml" to <xi:include href="file.xml"
* Fix usage of screen
* Remove unneeded link xmlns:xlink="http://www.w3.org/1999/xlink"
  declarations.
* Remove space before ":"

Partial-Bug: #1217503

Change-Id: Ie90a7c60be4646a95b7d8aec88773d199fc1a1b2
Merge "Cleanup HA Guide"