* add reduce_sum_op by add self-kernel

* set all ReduceKernel MPType for accuracy

* add float16 test script which input is integer number

* solve reduce sum float16 check_grad problem

* solve conflict and change test script for CI

* change kernel register for CI

* remove all useless template

* fix error message of l2_normalize, matmul, mean, etc. 
* add the test case for those ops

* Add the sum op to API 2.0, test=develop
* Fix the import meesage in common_ops_import

* set the default value of alpha for prelu to 0.25, test=develop

* add the call to __syncthreads(), test=develop

* fix the implementation of cpu prelu, test=develop

* repair the implementation of element mode prelu, test=develop

* modify test_prelu_op.py, test=develop

* refine reduce code to save compiling time and binary sizes, test=develop

* add reduce rank check to avoid bug, test=develop

test=develop

* wip simplify operator framework

* wip

* wip

* done test=develop

* clean test=develop

* fix test=develop

* fix deps test=develop

* fix cpu build test=develop

* fix tensorrt build test=develop

* fix tests test=develop

* fix test=develop

* fix cpu build test=develop

* Fix bug in reduce_op caused by PR #13534
* Fix output shape and enhance unit test.
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