* Add unittest for transformer prediction in dygraph_to_static.

* fix bug in fill_constant api. 

* Make transpose support size 0. test=develop

* Add transpose2 INT8 for mkl-dnn

test=develop

* Fix test_transpose_int8_mkldnn

test=develop

* Revert "Merge branch 'develop' into transpose_int8_mkldnn_2"

This reverts commit 34011bdb, reversing
changes made to 2ce6473f.

* Revert "Revert "Merge branch 'develop' into transpose_int8_mkldnn_2""

This reverts commit 23754dd7.

* Add template to TransposeMKLDNNHandler

test=develop

* Resolve conflict

test=develop

* Restore get_size and refactor

test=develop

There are mainly following fixes:

- take `DeviceContext` as the template parameter of math functors and OpKernel instead of `Place`
- remove `eigen_device` interface in base class  `DeviceContext`
- remove `GetEigenDevice` interface in `ExecutionContext` and base class `DeviceContext`
- remove unused `platform::EigenDeviceConverter`
- rename `REGISTER_OP_GPU_KERNEL` to `REGISTER_OP_CUDA_KERNEL`
- rename `USE_GPU_ONLY_OP` to `USE_CUDA_ONLY_OP`