The vhdutil utility is completely dead; the whole subsystem it relies
on was removed with [1] so it's not even vaguely possible to keep it
up-to-date.
I took the .raw images on a nb and used the qemu-img there (so Xenial)
and generated some VPC images; uploaded them to rackspace and the all
seemed to boot fine. If there was a problem, maybe it's been fixed on
either the qemu or RAX side in the previous few years.
Thus swith to qemu-img to generate the vhd images too.
[1] https://xenbits.xen.org/gitweb/?p=xen.git;a=commit;h=5c883cf036cf5ab8b1b79390549e2475f7a568dd
Change-Id: I3099d2ebb958370fcec623087a093b2c8dbdc6c4
a3e9e7f89e