Add client install option to disable logout over SOAP
    
    This is at least somewhat for testing to ensure that
    a mixed environment works but HTTP Redirect is the
    recommended mechanism in the spec so some may want
    to use only that.
    
    https://fedorahosted.org/ipsilon/ticket/59
    
    Signed-off-by: Rob Crittenden <rcritten@redhat.com>
    Reviewed-by: Patrick Uiterwijk <puiterwijk@redhat.com>