Added instructions for Havana to Icehouse upgrade on RHEL

I added instructions for the Havana to Icehouse upgrade process on
RHEL and derivatives such as CentOS and Scientific Linux. I also
addressed some issues in the equivalent instructions for Ubuntu.
Updated formatting for commands, file names, file extensions,
options, and a few other items.
Removed future tense where appropriate.
Updated book titles to actual names and surrounded with
<citetitle> tags.

Change-Id: I538e4e6d20ce11c95d4f60ae8f432f2eee20fcec
Closes-Bug: #1328987
Closes-Bug: #1328712
Merge "Added instructions for Havana to Icehouse upgrade on RHEL"