DNS Location: location-show: return list of servers in location
    
    location-show returns list of servers curently assigned to the location
    
    https://fedorahosted.org/freeipa/ticket/2008
    
    Reviewed-By: Petr Spacek <pspacek@redhat.com>
    Reviewed-By: Jan Cholasta <jcholast@redhat.com>