groupd: handle partition merges
    
    bz 546082
    
    The cman disallowed features means cman does not report
    nodes that rejoin and then subsequently leave of fail.
    But, the cpg api's do show these disallowed nodes rejoin
    and then fail again.
    
    The groupd recovery tries to match up the cpg and cman
    node failures, which doesn't work when cman won't report
    a disallowed node joining/failing.  To fix, just skip
    waiting for the cman nodedown event if the node isn't a
    member.
    
    Signed-off-by: David Teigland <teigland@redhat.com>