Install Guide: Remove obsolete files

Remove files that are not included anywhere.

Change-Id: Ie4b8560379c69ce2269e1af2c471b73606a2f769
backport: havana
Document cirros password in install guide

Describe how to ssh to cirros using password.

Backport: havana

Change-Id: Ie45c2d343ef2b6bc560d59a67224aa79ccf48e87
Fix typo in Admin Guide

Change-Id: Idae4aa007148d3f5c0fcad7da8555e7a23802a9d
Closes-Bug: #1245265
Merge "Install Guide: Remove obsolete files"
Merge "Document cirros password in install guide"
Merge "Fix typo in Admin Guide"