Given a name's history, flatten it into a list of deltas.
    They will be in *increasing* order.

def namedb_flatten_history( hist ):
    """
    Given a name's history, flatten it into a list of deltas.
    They will be in *increasing* order.
    """
    ret = []
    block_ids = sorted(hist.keys())
    for block_id in block_ids:
        vtxinfos = hist[block_id]
        for vtxinfo in vtxinfos:
            info = copy.deepcopy(vtxinfo)
            ret.append(info)

    return ret