Clean up Guest.__init__ so it is easier to reuse.
Clean up Guest.__init__ so it is easier to reuse.

In particular, move all things having to do with libvirt
into connect_to_libvirt().  That way, users who want to
create a Guest object *without* connecting to libvirt can
do so just by subclassing Guest and overriding
connect_to_libvirt().

Signed-off-by: Chris Lalancette <60b62644009db6b194cc0445b64e9b27bb26433a@redhat.com>

cernops/oz,clalancette/oz,cernops/oz,NeilBryant/oz,nullr0ute/oz,mgagne/oz,clalancette/oz,imcleod/oz,ndonegan/oz,imcleod/oz,mgagne/oz,moofrank/oz,NeilBryant/oz,nullr0ute/oz,moofrank/oz,ndonegan/oz