1. disable conv activation pass by default
    2. set fc_fuser'param with_relu false while mlu fc kernel does not
    support relu
    3. change fc filter shape from 2 dim to 4 dim while input dim == 4
    4. add ToFile func in mlu tensor for debug convenience
    5. enable 4-dim input in elementwise_ops
    6. add transpose2d in utility.cc