remove unnecessary template.

* add no_grad_set value check in op_test, test=develop

* update ops list, test=develop

* test=develop, fix geo Send & Init

test=develop

* remove skip_check in test_activation_mkldnn_op, test=develop

* modify lite commit id to support var_conv_2d cascade. test=develop

* modify lite commit id. test=develop

* polish backward prune, test=develop

* fix control flow op bug, test=develop

* add some unittests, test=develop

* fix unittest args, test=develop

* follow huihuang's comments, test=develop

* fix dataloader early reset bug, test=develop

* change implementation, test=develop

* fix ut, test=develop

* use function instead of lambda, test=develop

* follow comments, test=develop

* update external lite, test=develop

* switch WITH_TESTING to OFF, test=develop

fix timeout of test_dist_fleet_geo

* Implement a common python unittest to test the ir passes.
test=develop

* Save the results in np.array and support to startup on CPU.
test=develop

* Fix the unittest.
test=develop

* Add check_program to check whether the optimized program is different from the origin one.
test=develop

* Remove the inferface all_ops.
test=develop

* Add exception test in pass_test.
test=develop

* fix circular dependent

* try import layers.nn from dygraph
test=develop

* allow sublayer or param shadow attrs

* add unittest
test=develop

* change remove fn name
test=develop

* add half_async in the communicator
* fix DistributedStrategy

* add learning rate api; test=develop

* fix uni test converage; test=develop

* fix travis ci error; test=develop

* fix comment; test=develop

* fix example error; test=develop

* polish the api description, test=develop
Co-authored-by: Nzhongpu <2013000149@qq.com>

* remove unused inputs, test=develop

* remove unused inputs, test=develop

* update dtype, test=develop

* remove unused inputs, test=develop

* update op_use_default_grad_op_maker, tese=develop

* resolve conflicts, test=develop

* follow comments, test=develop

* update center_loss_grad, test=develop

* Fixed warpctc, test=develop

* Set lod level of sequence_unpad's output to 1 in compile time

test=develop

* fix the en doc and example code of warpctc, test=develop, test=document_fix