remove the blank space around the images and scale them well in PDF

Bug #1165621
Bug #1165616

Change-Id: Ia0028c051e61f5ed521fc162103c261a99064689
Expands the Boot from Volume documentation.

This commit adds some further information about booting from volumes. It
ensures the features are updated for Grizzly. Also removes a duplicate
section about booting from volumes. Also updates the Ops Guide with this
info.

Change-Id: Iac6a4caa36da388936543c7a3aaed3af1429bdd0
Fixes: bug #1163580
Merge "remove the blank space around the images and scale them well in PDF"