dlm_controld: even partition merges
    
    When a cluster partitions and merges evenly,
    e.g. 2/2, both sides were killing/fencing each
    other.  In this case, wait for stateful merged
    nodes to be cleared before fencing.  The side
    with the low nodeid will kill the stateful nodes
    (from its perspective).
    
    Signed-off-by: David Teigland <teigland@redhat.com>