* Add unit-test and example

* Fix type error

* Fix unit test cases

* Fix init error for cudaplace

* Change unit-test options

* initial commit

* fix bug

* end of file fix

* address comments

Rewrite mixed_vector.h

Remove 'numel' checker in compare op

* initial commit

* minor fix

* remove redundency

* address comments

Delete "API" section from "Documentation"

create optimize block in pserver program

Fix the bias of fc when num_flatten_dims is not 1 in fluid layers

Add python wrapper for layer normalization.

* Save the inference model in Python example of recommender_system.

* Add infer() in Python unittest recommender_system.

* Add C++ inference unittest of recommender_system.

Simplify the cmake of inference

refine error msg and add unit tests for cpp reader

Optimize return all optimize and related ops

Refine Channel's unit test

Fix CI hung

Refine distribute transpiler

GPU implementation for layer normalization operator.