[Libvir] PATCH: support Xen 3.0.5

[Atsushi SAKAI]

Hi, Dan 

  I test on Fedora7 test3 x86_64 but failed.
(Old version(which includes test3) works fine.)
virsh dominfo 0

libvir: error : no support for hypervisor (null)
lt-virsh: error: failed to connect to the hypervisor

Thanks

Atsushi SAKAI