fix dist compile

* Move Select to concurrency.py; incorporate outputs

* CLang formatting for concurrency

* Remove extra bracket - formatting fix - 3

* Comment fix

change boost download url to speed up download

Pserver prepare before run

Implementation of MKLDNN LRN

Demostration of cmake refine for HIP support.

* Temporarily fix bug for backward tanspiler when using parallel_do operator.

* Fix bug for backward tanspiler when using parallel_do operator

* Update index_en.rst

Update en version

* Update index_en.rst

Update refer to commits and thank you for the suggestion.

* Update index_en.rst

* Update index_en.rst

Update  refer to commits

* Add some contents

* Adjust the content of the English version

* Fix some error, replace word generate with build

* Replace document with documentation

* Adjust contents

* Make links more visible

Shrink batch_norm_grad's inputs

Build basic sphinx doctree for doc/fluid

Set WITH_DOC=ON in paddle/scripts/docker/build.sh and remove paddle/scripts/tools/build_doc.sh

Fix v2_pooling doc

Fix CI.

Add model average optimizer for fluid

Add float16 support to cudnn softmax kernel

Add float16 support to relu op

fluid distribute doc