sanlock: version interface
    
    Add the ability for a client to get the version
    of the running daemon.
    
    Start using the "version" field in the sm_header
    struct used for daemon/client ipc.  This is not
    the sanlock version, but the socket ipc protocol
    version.
    
    Signed-off-by: David Teigland <teigland@redhat.com>