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

Correct IR dependencies

Get more accurate file changes

Update hierarchical_layer_en.rst

* Update index_en.rst

* Update index_en.rst

* Update index_en.rst

Fix default value

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

Initial IR change

Fixed unittests for WITH_GPU=OFF and WITH_DISTRIBUTE=OFF build

fix dead link in high_level_api.md

better installation doc

fix mac build

* Added beam search API to fluid/contrib

* Change as review comments

* API.spec change

* Doc updated

Change the default value of the parameter 'drop_last' in 'paddle.batch' to False.

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

fix _clone_variable in optimizer.py

Delete overview.rst from api index

hide more apis

Update build script

 move contrib/inference to paddle/fluid/inference/api

fix set-e exit when checking api