Updated the entire installation section text, checked everything, cleaned up rackspace installation.
Clean up of unnecessary files.
Updated getting started on website.
Mostly changes to the html, moved pages, fixed links.

* Moved the introduction page to the en/latest/index.html home of the documentation and pointed all links there
* Fixed a broken link from+to homepage
* Fixed the javascript of the documentation navigation to allow expand and collapse multiple times.
* Fixed the one typo Andy pointed out
Merge pull request #620 from dhrp/documentation-review

Pulling the installation documentation update. Includes some timely fixes of broken links.