* Adding support for the sigmoid_cross_entropy_with_logits operator

* Fixing a typo in the cuda file

* Adding Python documentation for sigmoid_cross_entropy_with_logits_op

* Correcting typos in documentation

* Adding unit tests for sigmoid_cross_entropy_with_logits_op

* Addressing code review feedback

Add reduce op

fix compile error

Use scalar implementation instead of neon implementation to avoid out of range memory access in the tail conv3x3

should reset env every time

move Protobuf desc to framework

Remove OperatorBase::InferShape

User StridedMemCpy in Concat/Split Op

Use scalar implementation instead of neon implementation to avoid out of range memory access in the tail conv3x3.

InferShape in Operator should be performed in OperatorBase::Run.

* cond_op, recurrent_op and mnist might be changed in following PR

Fixes #4445

Make PyBind support C++ exception

Unify clang-format and add some missing clang-format

enable LoDTensor get number of elements at a specific level

* some enforce change

* add LoDTensor::NumElements(id,id)

* update

* init

* finish

* refacter interfaces

fix compiler warning from MKLDNNLayer and so on

refine mkldnn benchmark script

fix atomic issue on ONLYCPU mode

Fix doc of clip op.

Reduce elementwise warning

refine the catalog of FAQ