should not emit error when failing to open the hypervisor proc
  entry point.
Daniel

  virDefaultErrorFunc()
* src/sexpr.c src/xen_internal.c src/virterror.c include/virterror.h:
  adding more error reporting though the code, nearly complete.
* src/sexpr.c: added specific error function to avoid an error report.
Daniel

  API implementation, only CreateLinux is now missing.
Daniel

  Pause, Resume, Destroy, but untested yet.
Daniel

* src/libvir.c src/libvir_sym.version src/xen_internal.[ch]
  include/libvir.h: implementing hypervisor Version and Type interfaces
* src/virsh.c: adding a version command, WIP
Daniel

Daniel

  src/xen_internal.h: removed dependancy on xenctrl library, untested
  yet.
Daniel