Fix the Debian Heat install procedure

Removes unwanted steps from Debian install procedure.

Change-Id: I258d9f9e82304a804a58ec233a2329c0001ce41b
Backport: icehouse
Editing the Block Storage introduction

Sentence structure edits, and some content
editing for the Block Storage service introduction.

Change-Id: Iadc8c887a9a02e78a6a9f55bcf5a5e8d498d600d
backport: none
Implements: blueprint installation-guide-improvements
Merge "Fix the Debian Heat install procedure"
Merge "Editing the Block Storage introduction"