Description of problem:
If you do not have the pygtk2-libglade package installed, virt-manager will fail
to start with the following stack trace:

Traceback (most recent call last):
  File "/usr/share/virt-manager/virt-manager.py", line 70, in ?
    from virtManager.engine import vmmEngine
  File "/usr/share/virt-manager/virtManager/engine.py", line 24, in ?
    from virtManager.about import vmmAbout
  File "/usr/share/virt-manager/virtManager/about.py", line 20, in ?
    import gtk.glade
ImportError: No module named glade

It's easily fixed by installing the pygtk2-libglade package; the virt-manager
package should probably Require pygtk2-libglade.