should reset env every time

move Protobuf desc to framework

Remove OperatorBase::InferShape

User StridedMemCpy in Concat/Split Op

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

fix the conflicts of SoftmaxWithCrossEntropyOp with the latest dev branch.