Fix to include error message in instance faults

port the patch in 1013350 from Bill Darbie (bill-darbie) into latest code base.

incorporate one little comment from Russell about not specifying the default value twice

added a test case

Fixes bug 1013350

Change-Id: Id61f10bf2502fa57d2d26199ba9608e4566e8624
(cherry picked from commit ce41618c9c24a866ccac19461653eba3b8e6dca4)
Merge "Fix to include error message in instance faults" into stable/folsom
disallow boot from volume from specifying arbitrary volumes

Fix a vulnerability in volume attachment in nova-volume, affecting the
boot-from-volume feature.  By passing a specific volume ID, an
authenticated user may be able to boot from a volume they don't own,
potentially resulting in full access to that 3rd-party volume.
Folsom setups making use of Cinder are not affected.

Fixes bug: 1069904, CVE-2013-0208
Change-Id: I5f7c8d20d3ebf33ce1ce64bf0a8418bd2b5a6411