fix second-disk being seen as iso

With libvirt 1.2.8, the second disk is being reported as type iso, which
confuses libvirt. As a temporary workaround, intercept that and call it
raw.  Thanks to Serge Hallyn and Stefan Bader for the patch
(LP: #1372368).

Bug-Ubuntu: https://launchpad.net/bugs/1372368
Author: Serge Hallyn <serge.hallyn@ubuntu.com>
uvt-kvm create: add '--wait' flag

this adds '--wait' and all the related flags to the create create
subcommand.  so you can now:
  uvt-kvm create --wait myhost release=vivid