Find the set of peers that do *not* have this zonefile.

def atlas_zonefile_find_push_peers( zonefile_hash, peer_table=None, zonefile_bits=None, con=None, path=None ):
    """
    Find the set of peers that do *not* have this zonefile.
    """

    if zonefile_bits is None:
        zonefile_bits = atlasdb_get_zonefile_bits( zonefile_hash, path=path, con=con )
        if len(zonefile_bits) == 0:
            # we don't even know about it
            return []

    push_peers = []
    
    with AtlasPeerTableLocked(peer_table) as ptbl:
        for peer_hostport in ptbl.keys():
            zonefile_inv = atlas_peer_get_zonefile_inventory( peer_hostport, peer_table=ptbl )
            res = atlas_inventory_test_zonefile_bits( zonefile_inv, zonefile_bits )
            if res:
                push_peers.append( peer_hostport )

    return push_peers