Merge branch 'develop' of https://github.com/PaddlePaddle/Paddle into feature/update_sparse_parameter

Distributed survey

tensorrt convert init

* Added auto transform to beam_search_decode_op

* Added some comment

* Added unittest for beam_search_decode_op on GPU

* Fix CPPLint issyes in gru_kernel.h

* Fix CPPLint issyes in gru_kernel.h

* Fix Compile error

fix delete_ops

* add test float16 inference accuracy example

* complete the test

* clean code

* add argument parse and refine tests

* add shell script

* add float16 benchmark code

* refine code

* prepare for contrib/float16

* put things in contrib float16 folder

* update benchmark result

* further update benchmark report

* add float16 inference report

* update report

* update README.md

* change to .html

* use v2 api

fix pool with mask layer bug

Feature/clean blas

Wrap __shfl

* Add understand apiu with stacked lstm for new API

* Complete exam

Fix __shfl and __shfl_down for CUDA9.0

fix toctree in multi_cluster/index_en.rst

Improve trainer API

Refine distribute transpiler api

* "fix double type error"

* "fix ci"

* "softmax fp64"

* "fix momentum"

* "fix ci"