Admin user guide edits

Edits to the Dashboard: Manage Users and Projects section
Edits to the Manage Project Security section
All of this hopefully brings these docs in line w/ the Icehouse GUI
Closes-bug: 1194229

Reviewer comments added and niceness fixes as well.

Change-Id: Ib7ffa484eb817dbda0c046931aedea24e14404cc
Merge "Admin user guide edits"