* move conv to pten

* move conv to pten; test=develop

* fix bug;

* add conv cudnn impl; test=develop

* update

* update operator; test=develop

* fix bug; test=develop

* move operator and prepared_operator to develop; test=develop

* resolve conflict; test=develop

* remove useless code;test=develop

* add depency ; test=develop

* fix bug;

* add sig.cc ; test=develop

* fix use_op error; test=develop

* fix bug; test=develop

* fix bug; test=develop

* add conv3d register; test=develop

* fix star gan and conv_nn_grad test failed; test=develop

* add header; test=develop

* manul to recover to develop;

* resolve confilct; test=develop

* remove useless code

* fix bug;

* remove conv2d_cudnn; test=develop

* fix bugs; test=develop

* fix cpu rocm compile bugs; test=develop

* fix blas error; test=develop

* fix compile bug; test=develop

* fix windows compile error; test=develop

* fix windows error; test=develop

* resolve confilct; test=develop

* rename pten dir to phi

* rename namespace to phi

* rename infrt pten dir to phi

* resolve conflict

* rename pten to phi in cmake

* revert all infrt change

* change needed files

* fix infrt failed

* fix inference failed

* move operators/math/math_function_* to pten/kernels/func
* namespace from `paddle::operators::math` to `pten::funcs`

* refine structure for cuda and rocm

* update

* update

* update

* update

* stablize depthwise conv

* clean commend

* improve performance of DepthwiseConv(NWHC)

* [ROCM] update fluid operators for rocm (part5), test=develop

* address review comments, test=develop

* fix typo, test=develop

* fix depthwise conv gpu kernel bug, test=develop
* add more depthwise conv test, test=develop

* mem opt

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* refine code  test=develop

* refine code  test=develop

* refine code  test=develop

* refine code  test=develop

* refine with cub test=develop

* fix mkldnn test && remove comments && test=develop

* polish code && test=develop

* add only_forward test && test=develop

* optimize depthwise conv by register memory
* test=develop

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

* "re-commit "

* "picked up"

* "fix ci"

* "fix pdb hang up issue in cuda 9"

* Fix more CPPLint issues

* Fix more CPPLint issues

* Fix more CPPLint issues

* Fix CPPLint issues in operators/math and operators/reader