* 1. add the python api grad 2. add final and intermediate state vlog 3. change the python_api error logic

* add python api or close the check_eager=True

* fix the compatibility

* matmul

* disable unittests: test_elementwise_add_op test_scatter_nd_op test_gather_nd_op test_scatter_op test_index_sample_op test_elementwise_add_mkldnn_op

* refine the logic of prepara_parameter logic

* fix Tensor(gpu) 2 Scalar segment fault.

* add multi-attribute. (test_unsqueeze_op); add python_sig_out for customizing op sig out

* fix some bugs, support python_out_sig