[Libvir] 19/22 Disable unix, ssh and ext transports in Windows

.. because it's a lot simpler than actually implementing them. The user will see an error message to this effect if they try to use them. Rich. -- Emerging Technologies, Red Hat - http://et.redhat.com/~rjones/ Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 03798903