Add text about release notes

Add some texts that describes that the links go to release notes.

Also, some space reformatting because I edited in Oxygen.

Patchset clarifies the version numbering is for all but Object Storage.
Patchset revises based on reviewer's comment.
Fixes bug 1161896

Change-Id: I6bde10acaecb193281de185575c659ac69ebebcb
Clarify booting to a specific host

Clarify the sections on botting to a specific host. In grizzly, you
still need to use the availability zone flag, not the scheduler hint.

Rebases against master - please ensure accuracy.

Change-Id: I6c1e32f9618892cd1298955ed212ca7d935a4424
Merge "Add text about release notes"
Merge "Clarify booting to a specific host"