Don't relocated multi-node core reservations

Do not automatically relocate an advanced reservation for individual cores
    that spans multiple nodes when nodes in that reservation go down (e.g.
    a 1 core reservation on node "tux1" will be moved if node "tux1" goes
    down, but a reservation containing 2 cores on node "tux1" and 3 cores on
    "tux2" will not be moved node "tux1" goes down). Advanced reservations for
    whole nodes will be moved by default for down nodes.
bug 2326