* speedup split_op
test=develop

* speedup split_op
test=develop

* rename ConcatGrad to Split

* refine concat and split
test=develop

* fix compile error

* Add affine channel op.
* Update code and add Python API.
test=develop
* Update API.spec
test=develop

test=develop

test=develop

* "fix compile error"

* "fix ci"

* rerun ci
test=develop

* test=develop

rerun ci

* refine reduce by cub
* optimize KernelDepthwiseConvFilterGrad
* optimize depthwise conv and reduce mean and reduce sum
* fix bug: dilation
* cuda arch and cuda 8 compatible

test=develop

* refine seq_softmax_op

* fix seq_softmax

* use cub in seq_softmax

* Improve and fix fake_quantize_op.

* cudnn widndows

* "add comment"

* "windows support"

* "fix cmake error"

* add flatten op

* refine regularization for selected_rows

* clean lookup_table

* refine rpc_server_test

* temporally disable rpc_server_test

* fix rpc_server_test

* add unit test

* also convert tab to space

* "split into multiple .ccl"

* "refine file structure"

* "refine files"

* "remove the cmakelist"

* "fix typo"

* "fix typo"

* fix ci